This brings to mind a former neighbour. On various occasions we were on the EC together and on other occasions I had reason to knock on the doors of all the neighbours over some issue or other. This particular rather proper lady was always in pyjamas and dressing gown whenever I visited and always apologised as if I had caught her in a very unusual occurrence. It really didn’t bother me in the slightest!
Another very elderly neighbour admonished me for discretely looking aside rather than waving in a friendly fashion when passing her unit and seeing her sitting up in bed.
If your EC wanted to make anything of your snuggly neck-to-ankle jim-jams I would expect them to be laughed out of court. Tell them to grow up!
More seriously, I think by-laws generally only have any validity if consistent the strata laws and other higher laws. If you were dressed in a manner that would not be inconsistent with general public decency laws I doubt the by-law could be applied, not that I’m a lawyer. Indeed, I can’t see the point in it. If you breach a general law use that, if you don’t breach the law then I don’t think the by-law is much use.