Exploiting a Minotaur's horns

[DivisibleByZero]

This may be a typo and not RAI, but RAW from UA is that they are weapons

RAW from UA doesn't exist. That's an oxymoron. Those are play test rules, not official rules. If it isn't official, it can't be RAW.
I 100% guarantee you with absolutely zero doubt in my mind whatsoever that, if this ever becomes official, they are not considered weapons, and that the wording will be changed to something along the lines of: "When you take the attack action you can use your horns to make a single melee attack which does 1d10 damage" or something along those lines, so that it isn't specifically called a weapon. I guarantee it.

But you should never, and I mean absolutely never, use the term RAW when discussing anything from UA. UA has no RAW because UA isn't official.