It’s political polemic written by a prominent Canadian trade unionist and communist party member so no it wouldn’t pass muster as an academic source, but it was written with rigor and he cites his sources.

What he writes is a collecting of facts established by others that he then peppers with (righteous) polemic, and it’s that polemic which makes it unsuitable for academia rather than the reliability of the information within it.

The three major claims are

1. The holodomor was not a genocide, which represents the historical consensus on the topic until about 10 years ago when Ukrainian nationalism became a very useful tool for the west which is when Timothy Snyder and Anna Applebaum started popularizing the famine-as-genocide narrative that previously was confined to Ukrainian nationalist circles. For a more academic approach to this topic I would recommend the work of Mark Tauger who is an economic historian who went deep into the data and chose to prioritize data over anecdote and he makes a very convincing case that the holodomor was a famine, not a genocide, and indeed more Russians died in that famine than Ukrainians, and the single most affected ethnicity was in fact the Khazaks as the famine affected all southern USSR. He also includes data that shows the famine in Ukraine was greatly exacerbated by the Ukrainian nationalists - who were supported by Poland at the time which had already conquered parts of Ukraine and Belorussia as part of the Polish military expansionism of the 1920s and 1930s. Most convincingly he explores the efforts at famine relief the Soviets undertook. He got into a fight with Applebaum where she criticized him for being a “genocide denialist” and he criticized her for relying almost exclusively on anecdote. Prior to the Ukraine war, about a third of the wiki page on the holodomor was about Taugers work on the topic (and the thorough debate he had with Wheatcroft which is a series of letters you should look up, Tauger vs Wheatcroft for the most thorough and thoroughly academic exploration of the topic.)
2. That Canada resettled the Ukrainian SS division, which committed crimes equal to the worst crimes against humanity including organized genocide of Jews, Romani, and other ethnic minorities in Ukraine, giving the Nazi battalion refugee status and carefully looking the other way to avoid acknowledging the very obvious and demonstrable fact that they were war criminals and part of the SS. This group, also known as the OUN, formed a community in Canada which is still extremely nationalist in character and this community are the ones you see flying nazi symbology quite openly in Canada (such as the black sun) and who erected a monument to nazi SS divisions to “honor their ancestors.”
3. That the holodomor-genocide idea originally comes from Nazi propaganda when the Nazis were seeking to justify their war of conquest against the USSR and to cultivate a “fifth column” of Ukrainian nationalists, seeking to build upon the efforts of Poland to split Ukrainians away from the USSR into the Polish orbit. He shows how the photos used in the Nazi propaganda were first debunked back in the 1930s (eg photos depicting earlier famines or famines in other locations entirely) but then found their way into supposedly respectable academia mostly at Havard and mostly historians who interestingly enough were “former” members of the OSS during WW2 (information and propaganda officers who “retired” from that role to take up positions as historians at Havard) and a lot of the emotive imagery used to prove the genocide were debunked as fake news close to a century ago and furthermore were debunked as fake news written by Goebbels and the Nazis no less.

If you want solid academia that relies on data then refer to Tauger. He’s the only historian I’ve encountered who actually preferences economic data (which he rigorously cross checks against other indicators to ensure it’s reliability, eg comparing grain yields to prices to ensure the data is consistent across various dimensions). He has been trashed over the past decade mostly by Applebaum who relies on anecdote and human stories, frequently from the Ukrainian SS refugees in Canada and also has at times used the same photos the Nazis used that were of previous famines in other locations.

The other major historian who pushes the genocide narrative in the west is Timothy Snyder mostly in his work “bloodlands” which was written for a popular audience rather than an academic audience, which also is notable for relying significantly on anecdote. His work also suffers from the way he tells his story, which he presents alongside the Nazi atrocities and sometimes Polish atrocities, seeking to join all these events together in a narrative sense by telling these accounts side by side even though there is little reason to group all these events together.

Edit: oh and Wheatcroft is another much earlier proponent of the genocide narrative who attempted to engage Tauger on the data and Tauger gave him an absolute smack down in a series of essays, which were published but written as letters more or less. Wheatcroft ends up basically name-calling as Tauger gives a veritable smack down based on data and for a while this represented something of the consensus position, that it was a famine mostly driven by natural causes, partly exacerbated by collectivization, that the Soviets paused collectivization once they realized how bad things were on the ground, how the Soviets also engaged in famine relief efforts, and how the single biggest man-made contributor to the famine was the mass slaughter of animals especially horses and cattle by the small percent of the population who owned a lot of land, not a genocide.

Also other historians who are extremely hostile to the USSR such as Stephen Kotkin also say it wasn’t a genocide, which indicates the general consensus that existed on this topic before Ukrainian nationalism became useful to US foreign policy goals.