Without knowing the nuts and bolts of the network like some people on here do I would say, yes you could have that system. And it sounds like a great idea.
Atlas Atlas - Things on Autonomi
and
Friends :IF: Friends - the messenger you'll never want to move away from
Have already shown that systems can be built with this kind of functionality. But they are custom applications rather than being based on something existing like Git. I don’t know if Git would be able to use Autonomi storage natively.
Does your idea have to be based on Git? Or are you open to building something custom with the exact features you need?
There is a competition - Impossible Futures Timeline & Network Updates - which has already had its first round but there will be more rounds later that is for the programmers of novel applications to win funding for their idea.
And Welcome!