Hi - join the club... When I first read through the rules I thought exactly as you did, it was the phrase 'have to' that was so emphatic. I am new to the Forum and am sure there are probably some linguists out there who can help us. I had a look at the German rules and, from memory, based on my O-level German (shows you how long ago that was), the expression 'darfst du einen Meeple ...' is along the lines of 'you may use a Meeple according to the known rules but you cannot put the Meeple on the bathhouse itself'. The important thing is that word 'may'.
So my reading is that, after pulling the BS (Barber-Surgeons) tile we have the the option of placing a Meeple as per normal rules i.e. Road, City, Field or not placing a Meeple on the tile at all.
Lets see what the others think.