Actually the wine package in Tumbleweed comes with mp3 support since some time, and that’s what causes the conflict.
So, there is absolutely no reason to install wine-mp3(-32bit), and you shouldn’t do it at all.
I.e. I concur, the best solution here is to use --no-recommends (or lock/taboo wine-mp3-32bit).
The wine-32bit package doesn’t obsolete wine-mp3-32bit though, that’s an oversight that has been fixed already, but the updated package is still pending legal review.