Not building housing will definitely make things worse (see California). Some subsidized units is better than nothing and hoping for private developers to solve the problems at the absolute lowest level of the housing market isn't going to happen.
I wish DSA had some sort of coherent housing policy but it seems like all they bring to the table is reactionary NIMBYISM.
My basic understanding is the developer promised some subsidized units but in my city that tends to be not targeted at the most at need.
The alternative is it stays a golf course and there was never any serious plans for the city to build anything because a private developer owns the land.
I'm not a local though so my knowledge is fairly limited.