I can't see more new Pokemon either(bar Iwanko and Nekkoala) but like I said in the gen 7 confirmed thread, I think there is something else coming. If you look at the Japanese website and the videos for each separate Pokemon, its obvious that what we got today was cobbled together at the last minute, as crazy as that sounds. They took all 7 introductory videos for each Pokemon's page and looped the main theme over them, I am dead certain on this. Otherwise if this was the actual trailer, stuff like the 4 Pokedex Animation vids at the end of each Pokemon's introduction would not be there as well, which is the prominent feature of the individual Pokemon Vids.
Swarm Change probably swaps in as the default ability when you gather more cores. No idea how the hell this is going to work if you can have both 10% AND 50% going at the same time. I say cores because it seems like the cells needed to reach 50 or 100 are gathered in the ability. Gonna fun to see how this works out in the end.
I think Aura Break was given to it in 6th gen because the forme change mechanic for it didn't exist. My theory is that 10% and 50% have Swarm Change, and Complete has Aura Break.
Chrysalis is the name of a butterfly pupa. I'm not an expert on beetles, but Charjabug doesn't really look anything like a real beetle to me - I'm just going to keep assuming it's meant to resemble a battery. Though I suppose your explanation is correct in a roundabout way because Metapod, an actual chrysalis, is extra hard and rigid.
