The first crates to be eliminated will be the Champion series. That's Champion Crate 1, Champion Crate 2, Champion Crate 3 and Champion Crate 4. To view what's contained in each one, there is a helpful page on the Rocket League Wiki. They'll no longer be dropped after matches following Rocket League's "next major update," which isn't dated but is set for this summer.
Looking toward the future, the plan is to Rocket League Keys discontinue crates approximately six months after their initial launch. This should make it easier for players to know roughly when they can expect a crate to be eliminated from the drop system. The developers have also said they'll be announcing well in advance when crates will be retired.
Rocket League is still going strong online with regular players and a few different esports comps happening around the world, and one of the things that have kept the game popular is the soundtrack that you get to listen to during the start and sometimes in gameplay. Psyonix has decided after three years, they’d like to change the tone yet again and are looking to replace the main theme music of the game. But before they do so, they’re looking for your help in deciding what it will be. Below is a tweet they sent out for the weekend, asking for fans to decide on their new tunes.