I wouldn't be but its a matter of personal choice. My dd has only in the last six weeks decided to cut back on milk and eat more food. Sheis 13m and has at least four milk feeds still between 6pm and 9am as well as offering a sippy cup of cows milk with morning tea, lunch and afternoon tea at daycare. She has access to water bottle all day.
Personally,we followed the food s fun until one mantra so for us it makes sense that she still has a lot of milk in her diet.
Bottles cause dental issues more so when they are put to bed with them and use them as a comfort like a dummy. If dental issues were something you were concerned about there is really o need t cut out milk, just assist in get brushing after the bottle rather than going to bed with one.