I'm just wondering. It does make sense that it would though.
Gastro Acid suppresses the target's Ability while it remains in battle. Gastro Acid does not affect Multitype or Stance Change. Pickup and Honey Gather can still find an item after the battle even if suppressed. Despite being a Poison-type move, Gastro Acid affects Steel-type Pokémon.
Gastro Acid only doesn't affect Stance Change or Multitype, therefore it will suppress Parental Bond (so the Kangaskan will only attack once).
Source
Yeah, Gastro Acid will cease effect of Parental Bond. Unless Mega Kangaskhan switches out, and back in again. :3
So, Gastro Acid practically murders the baby. :D
Hope I helped. :) Source