Now any threats that they make are probably just bluffs, but there's no way that senior staff of a defunct division would be arrested for something done by their former company, and the idea that there'd be any extraditions going on seems unbelievably far fetched to me.
Brexit or not the UK still has a lot of soft power, it’s still a G7 member and a large economy.
Other countries won’t look too kindly on a corporation ignoring a major and very well respected regulator even if their interests aren’t impacted by that particular decision.
The rule of law is something countries fight to preserve and it’s very much a collective thing.
If microsoft decided to no longer do business in the UK (not happening - it's a bluff) it would not be beholden to their decision.
It would be a different situation if either company was based in the UK, but that's not the case.
There is a very big difference between that and seeking permission and being told no and then acting like a 5 year old which is what Microsoft and Activision are doing.
and the shareholders would want the current board out
not to mention the complete total global reputational damage of ignoring a G7 country's competition regulator