Are the conditions similar enough? China was after a second world war when monarchy worldwide had far less influence than 1917. While they were facing outside pressure after the revolution it was in proxy wars and via more significant rallying points such as Taiwan/Tibet. Both of those serve that same role but a 1917 monarch would be more culturally/politically relevant. It being a European monarch would mean the revolution is right outside France/Germany/Nonce Island instead of mostly threatening whatever colonial holdings around China that Europe could still manage. The empires opposing Bolshevism in the 1920s were the strong victors of WW1 instead of the mostly ravaged opposition to the CCP excluding the US, and they did just that with the Dalai Lama.

So it happened once and has been a disaster pretty much every other time.

They rose up anyway but without a common goal. The Syrian Islamists without ISIS are less cohesive than they were with that centralising force because all of the various factions have competing interests. I would rather face the latter than the former because they can't coordinate as well.

You're assuming that the Romanov deaths happened in a vacuum, that there weren't conditions that resulted in that moment and conditions that could have been created from any action in that moment. What exactly do you think is going to happen the moment the Bolsheviks walk out with the Romanov children and say "Here you go, remaining royal families in Europe. Look how civil we are as we destroy everything you represent except for a status symbol."? Are those empires going to not immediately turn on the Soviets? Are the Whites going to respect Bolshevik family values? Is anyone going to be meaningfully swayed by that action other than armchair moralists a century later?

Or are they going to say "yeah this is the rightful ruler of Russia" and then intensify a united effort to defeat the Bolsheviks, at which point they would install a leader whose regime is responsible for pogroms. If that's the case, are you willing to accept those civilian deaths somehow morally better and under what criteria? Because they aren't dressed in fancy clothes paid for with the blood of peasant children?

edit: Found it. There was an early Soviet agitprop poster. "Learn to read and write. Children of literate mothers die less often." The desperation behind the need for that poster reflects a depravity that is accepted because it's background noise. How many of those children dead to their mothers' illiteracy as a result of Romanovs is one Romanov child worth? Children are dying either way so we're talking triage.