I bred a Torys R Us Event Manaphy, which comes with the moves Heart Swap, Water Pulse, Whirlpool, and Acid Armor. I bred it with a Ditto. The resulting Phione egg does not pass the PKHeX legality checker because the offspring will know Whirlpool and Water Pulse (as they are TM moves). It says that the moves are not valid in an event egg, of course, this is not an event egg. I have not edited this save or any pokemon in it.
https://imgur.com/a/7T3ESHo