What does the triangle with the ! Inside it mean on my games

Hi, I hope you're doing great out there. I am an Independent advisor and I am here to help you in regard to your concern.

This may mean that you don't have the license for the said games, it can be installed via game share that is longer being shared with you or a game that was previously on the Xbox game pass library that you also don't own.

The controller+ it has DLC

I believe that the controller icon indicates that you can join a friend in the game and the other icon you mentioned either means that the game/app has either been updated or there's an update available for it. I can't remember exactly, but I'm pretty sure
it's something like that.

The white triangle you are talking about means that it has recently been updated since the last time you've played it, notice as you start the game, it disappears, this was a small addition to the April update I believe otherwise the march update

The triangle means it's a game. The + means it's an add-on. usually