Corporations control how it's rendered. Can change the glyph around as they see fit. Famously done with the gun emoji.

Corporations control how all shipped font glyphs are rendered on their platforms. An emoji isn't fundamentally different.

Use open source software if you actually care about this.

I agree with you on the gun emoji thing, that was gloriously retarded. But all in all, you can always choose an open source rendering of the glyph.

I think the point is you can't have the people you're sending the emoji to to use your open source rendering of choice. That's how it's corporate controlled. In contrast, corporations don't have as much choice in how plaintext glyphs render, without making them potentially unrecognizable.

Couldn't they just make their font have a ligature so that :-) turns into whatever they want? That's how some programming fonts make stuff like -> or != look different.