Rotom changing forms but keeping moves

[pyrromanis 70]

I put in Wonder Trade my Rotom-mow that knows Leaf Storm. Bibs received it but instead of being in it's mow form it reverted to the normal one. He tried to put it back in WT but the game detected an illegal move, which it was Leaf Storm. I don't have a screenshot cause bibs is dumb but theoretically you might be able to get other Rotom forms with more than 1 special moves