Yeah if the intention is to be a LGBT ally
then their heart is obviously in the right place. But TBH, now that I think about it, it might just be that the term "partner" in general that I have an issue with, even when applied to gay folks. I'm just not really a fan of the term and most of my gay and lesbian friends still tend to use "boyfriend" and "girlfriend". If your trans or gender fluid etc, I guess "partner" is maybe the best available option though hopefully that changes. The trans community deserves a better, more affectionate term IMO.
Yeah don't think anyone uses the term "lover" without irony these days. Unless maybe swingers, who are called "sex positive" now and I think they use new terms for their significant others as well but I can't think of them.