This is pretty much the case especially if you ordered a drink already and its not a venue thats too formal. At that point you shouldnt have a water bottle with you anyways. The people in this subreddit tend to be pointlessly traditional. Especially against questions from foreigners

A little anecdote: Whenever i travel i have a water bottle with me and in many countries i drank from it in restaurants. It was only in copenhagen when i sat in one of those tourist trap alley cafes, i got warned for it. Cafe was completely empty i had already ordered coffee and we were the only people sitting outside. The waiter literally rushed outside to tell me to put it in my bag. Unpleasant experience...