IDK if the bug is back or it was never addressed but my sim was in a towel and had herself a lovely beekeeping hat on as well, very fashionable.
June - last edited June
The easiest way to fix this is to use the Dresser module of MC Command Center and run the command to remove all accessories. That will usually be enough to stop a Sim from being generated with them again in the towel outfit, but if it's not I just blacklist whatever accessories the Sim is wearing for the towel outfit, and then it definitely doesn't happen again.
Having this plus other graphic glitches since June 2019 game update. Was planning to buy island expansion but have since stopped playing the game until an explanation can be found.
I understand @LuvMySimz , but considering the number of problems with outfits in the game and the lack of attention to them by Maxis, I was simply posting an option for people who already either use MCCC and didn't know about what I posted or for people willing to try it that don't use it already.
I would love an official Maxis fix for this problem, the broken GeekCon outfits, and the other outfit bugs, but in the meantime I'm willing to do what's necessary to alleviate the frustration.
July - last edited July
I just ran into this same issue in my game a few moments ago. I too have the Spa pack. When on a Spa lot, choosing to wear a robe makes my sim wear random accessories along with the robe. I've never chosen those accessories before. It's confusing and frustrating.
I noticed this for the first time last night, Sims at the gym wearing a towel and beekeeping hat - although in this case it seems that only Sims from played households were affected - for once random townies seem OK with no accessories