>>29597143>>29597192>>29597265>>2959828That's not how it actually works. Sleep Talk is an Egg Move so it'll pass down regardless of how it's learned. You'd have to use a Move like Double Team, which is not an egg move for Wailmer and it won't pass down since TM moves no longer pass to offspring. If it's flagged as an egg move it'll pass down because it's an egg move.
The list on Serebii just doesn't list TMs as potential candidates despite the move being flagged properly.
It kinda defeats the purpose of breeding for the move if you'll just teach it as a TM anyway.
(Guy with Bonnie images is correct. Just arguing poorly.)