I suggest we remove OOUI icon packs from MW 1.25 release. They are rather poorly done right now and it would suck if that was people's first impression of them. (Or worse, if they started depending on the existing icons and misfeatures.)
I would, however, be the one to get shouted at about icon incompatibilities, because I've had the misfortune to implement most of the code supporting the current unfortunate icon set, and because I intend to be the one to get it sculpted into something more sensible.
If it's any consolation, T91152 will also be a breaking change in this regard, and I intend to do it soon.