Technically speaking, yes, you could have a Muddy Tidechaser with Heal as its first ability.
However, they only changed it so that all families have a skin that has Heal as its first ability: for instance, an Automaton Egg has a 50% chance of getting Heal on a Robobuddy.
Another example is the Green Ant. The one I have in my current Pet Yard has Attack Close as its first ability, as it was hatched pre-Wardrobe. However, on my alt MrAcclaim (pronounced Em-er-acc-lay-uhm), I have a Green Ant with Heal as its first ability.
Back on topic, this would probably make getting a good ability combo for Pets much easier…in a pay-to-win way, to some extent.
It takes away one of only two unique things you receive when hatching an egg - the skin and first ability. Especially since it’s for gold…