This is perhaps a bit unfounded. We don't know what he drinks from for the rest of the day, one bottle as comfort before bed is not such as issue I'd have thought? I've met many kids who found it hard to give up that bedtime bottle and the only issues I've heard of is it making it harder to overnight potty train and needing more thorough teeth brushing.
Happy to be corrected on this, but I do think we need to be mindful not to place blame for any issues R may or may not have..Hunch has been so vague we don't actually know what delay there is if any!