Xbox get rid of on screen keyboard when using K&M

Yes it is but just for some few games and not all games. Fortnite for example is allowing you to play with m&k(mouse and keyboard) but you are getting queued against m&k users, so PC Gamers, PS4 Gamers with m&k and Xbox Gamers with m&k. You can use an
adapter to play with mouse and keyboard on every game. And the console and game are thinking, you are playing with a controller. And even in Fortnite you are having the advantage to get queued against controller players.

Here is some support information on using k/m.

https://support.xbox.com/en-US/xbox-one/ease-of-access/mouse-keyboard

It's supper annoying when people use mouse and keyboard that doesn't even support it

You can use M&K on all games now.

You can pretty much use any keyboard, but not every game supports M&K

While I can't speak to that particular K&M set, I HAVE attached an Apple branded mouse via USB just fine to play Sims 4 on my Xbox.

As long as the game supports K&M on Xbox, that should work just fine.

Here is a list of K&M enabled Xbox games:

https://www.trueachievements.com/keyboard-and-mouse-support/games