It hasn't received any new games whether Arcade or Retail that I've seen which is pretty disappointing, but Xbox 360 has been active for a long time so its closure is likely coming real soon. Also, I noticed that PES 2018 demo was removed from the store while the 'newest' is now FIFA 17 demo. Well, download the games/demos/trailers from the Xbox 360 store you want because sooner or later all of it will be taken down in some way. Just as Indie games were, we can't download Indie demos anymore but at least the Indie full games purchased we can, it's a shame because there were Indie games I'd have purchased if I had known ahead of time they were going to be removed in its entirety (it was announced but I didn't read it nor was it actually a popular article on YouTube/IGN).
Stuff just gradually disappears from the 360 store when licences expire for content used in the game, for example certain cars in Forza. Quite a few arcade games have already gone. We have tried to preserve Delisted Xbox 360 Marketplace Content here and have shared trials of games where possible. Sooner or later your right a lot more stuff will go, I think Xbox Live for the 360 will stay around for a long time to come yet, as quite a few games are backwards compatible on the Xbox One and enough people play 360 games online to make it worth while keeping the servers on. Plus they don't have the hard coded limitation of 100 friends like on the original Xbox, so in theory the 360 shouldn't hinder the advancement of future Xbox Live improvements. Its been well over 5 years since the Xbox One launched, so at this point if the 360 gets anything new its a bonus, probably only games that get milked every year like Fifa will get future releases on the console, Fifa got a release on the PS2 each year for 14 years! Saying that the Fifa game this year will mark 14 years of releases on the Xbox 360 also, so it will be interesting to see if it gets released next year too. Like most modern consoles to enjoy content indefiantly a hacked console will be required. For Jtag / RGH hacked Xbox 360's the vast majority of content has already been preserved outside Xbox Live. Theirs a few people on Digiex with many terabytes of Xbox 360 content.
The console did receive an official system update earlier this year, which is pretty amazing considering the Xbox One has been out for so long now. And yes, content being able to expire due to whatever reason is, like, the dark side of digital marketplaces. You could compare it to physical copies getting out of production, but at least physical games can be exchanged with others. The first time this upset me was when the Turtles in Time remake was removed after Nickelodeon obtained the license. It's okay for an IP to change ownership, but to wipe the past like that.. That's pretty rude.
I do somewhat regret not buying Turtles in Time when it was available nor OutRun Arcade, all I have now are the trial versions which isn't really much but, eh, something. At least I bought The Simpsons Arcade which I love so much!