As an argument, that's rather thin. You'd need to show that it has been used "often" over the last decade or so to argue that it is common usage. That said, the use of coconut milk would suffice to prove your point.

Steak, burger, meat, etc., don't fall in this category, but personally, I find vegan burger more understandable than the technically/conventionally more precise plant-based patty. It also doesn't distract from the original word: if something is called burger, you can be pretty sure it's meat.