@cfrank I thought it through deeply enough (you might find some old post about it from me from long while back), and I got enough initial reactions. Conclusion for now is: this will be a bottom-up change. The people who have invested in "Approval" are too hesitant to embrace a rebrand and aren't facing enough catastrophic rejection or something to force it. You can test for yourself that every naive lay person off the street understands SO MUCH more readily when you say "Choose any" rather than "Approval" (and that they also feel constricted about "approving" candidates rather than just voting for preferences, as in how people don't approve of lesser-evils but do vote for them)
So, I think the more people just say "Choose-any (aka Approval)" over and over, there will be a slow shift to more and more use of just "choose any" until that just becomes the norm and the main advocates embrace it too. This bottom-up approach is the best path forward IMO, but I'll be happy for anything that fixes this problem.