I read that by the time MS acquired Tango and Hi-Fi Rush was released, most of the developers and management had already quit, so MS basically only owned the IP anyway. Tango allegedly had nothing in the pipeline, and the few people who were left were working on nothing, and there were no leads to start the process of developing a new game.

Not sure how true it is, but in that case it would make some sense to just shut down the studio, because the alternative would be essentially starting a studio from scratch.

Of course, this begs the question of why all these developers left. I can speak from experience a bit here. When it was announced that a small company I worked for was acquired by a mega corporation, everyone quit because the company we were being acquired by had a reputation of being a horrible, toxic workplace. This is obviously just speculation, but I could see something similar happening here.

MS usually buys competition to erase it so there's nothing too surprising about this. And no, Bethesda and Blizzard won't be treated very differently in the long run. That is after every material of everything the studios have ever worked on is fed into datasets to train AI for who knows what.

If this deal went through in time to save Tango, as the press release states, this just must have been how long it took for the paperwork to go through.