Ever since I was level 175, I kinda realized that I never got level up rewards, I have the level 175 emote, but at this point now I'm level 300, and have never gotten level up capsules since. I heard a friend last week say that they wanted to "open up some capsules" before they joined my room.
So in conclusion, after some time, I've been struggling without ANY LEVEL UP CAPSULES since level 175, and I haven't gotten any of the emotes either.
This happened to me around the time that RP had issues so my original thought was that it was tied with the RP stuff, but after hearing from the friend that they were opening capsules, it got me wondering.
EDIT: Note that I still get S chests, so that hasn't been a problem when I get S, I've only had a problem with getting capsules from LEVELING UP. Everything else with hextech crafting is totally fine.