Or, maybe it's because of their strong bond with their trainer that the Pokemon is willing to go to such lengths in battle.
Yeah Sycamore may have flunked out of mega evolution college but the practice has been around for hundreds of years in-universe so I'm sure the new information isn't necessarily
new in-universe. Aerodactyl's site flavor text implied scientists have been researching it for a while. The ~bonds~ are probably just retconned into controlling the pokemon in their enhanced states; something Korrina does in the anime, actually.
I also have my doubts that a random rotom has such indepth knowledge all on its own. Honestly the pokedex has always felt like it needed to be a collaborative affair based on research and not a "oh i caught this, let me tell you literally everything about it" thats made even sillier by it being
a rotom.