If they had that, they’d no longer be FOSS and instead “source available” and half the community will raise the pitch forks. Best FOSS licence to protect against this sort of thing is AGPL because it’s toxic for corporations. But even that could be used in this case if they had the source on the same computer imo (IANAL though)

I suppose there’s not a lot of communist leaders to choose from in general, but Kronstadt happened on Lenin’s watch and it would be a bit disingenuous to pretend this was controversy free amongst the left and working classes.