I’d love to help, @jonah.deleseleuc, but you know I don’t work for Bubble, right? 
The above being said, there have a been a good number of folks who have reported capacity spikes (and who have also gotten the resulting email) in the past few weeks or so, and I am actually one of those folks (I got a capacity email for an app that hasn’t been used for years).
I brought this matter to Josh’s attention behind the scenes, and he wrote about it a bit in his monthly community update for June. Check out the first paragraph under Things on our minds.
Anyway, I hope this helps a bit, and it couldn’t hurt to reach out to Bubble support to have them take a look at your app and make sure there is nothing to actually be concerned about.