I worry that this may lead to an embrace/extend/extinguish by Google given that they have a tremendous influence through Chrome.

After all what's their angle here? Almost every browser extension under the sun has a Chrome version due to its immense market share. It seems like a good way for them to later potentially push for changes that would make, say, ad blocking easier (under the guise of performance or some such).

I consede that it's a bit tinfoil-hatty, but I have very little faith in Google these days.