Evil idea is to change symbol-only commentary into meta-only commentary or something as the compromise.
I'm fine with that. My only complaint is that the meaning of meta-only isn't entirely obvious, but I can't think of a better name. Both tags have the same purpose of saying the commentary doesn't contain any "real" translatable text, just hashtags or emojis.
One problem though is that on some sites like Tumblr, sometimes the hashtags are the commentary. They're used to provide the actual comments on the image, and not just as character/copyright tags. In that case hashtag-only commentary can't safely imply commentary, since if the hashtags contain meaningful non-English text about the image it should be tagged commentary request instead. Although I guess calling it meta-only commentary could sidestep this problem, since these hashtags wouldn't be considered meta-only in that case.