Why are animals food, though -- just because that's how we currently treat them? I think the status quo bias is obvious here. After all, you'd never want people to start farming humans, right? So why agree that it's okay once it starts?

Could your argument have been used to justify slavery?

Yours certainly could. It's a fully general moral counterargument.

You have ethics that aren't mine. You want to keep your ethics and not convert to mine. Other people have different ethics to me and also different ethics to you. You don't approve of those other people keeping their evil ethics because they puppy kicking baby eating status quo loving slavers. Therefore, you should convert to my ethics.

Having a preference and keeping that preference isn't a status quo bias. It's the status quo.