Might sound similar logic, snoozer, but it is totally different!
Of course women should have as much information about feeding as they wish, but if they are planning to breastfeed (and the huge majority of women in the UK plan to breastfeed these days) , why should they get info about bottle feeding antenatally in a group with others who also plan to breastfeed? That normalises formula feeding, by undermining this plan to breastfeed - almost like saying 'we know you want to breastfeed, but formula feeding is what most of you will do, so gather round and watch me demo this'....what on earth is that doing to their confidence (and we read here every day, confidence is very important when it comes to bf)? If anyone wants an individual demo of making up a bottle, then of course they should be able to ask for this, and ideally, have it demo'd to them at home, in their own kitchen, where they can have a go themselves.
To return to your questionable analogy, teaching abstinence has been shown to be ineffective at delaying first sexual intercourse, so why this would be 'preferable' in any circumstances, I don't know. Yes, teaching about condoms normalises teenage sex. This is only a bad thing if you think teaching abstinence is a viable option, which it isn't.
Making up a bottle of formula can be done unsafely - there are rules about water temperature, cleanliness, how and when to add the water and so on. Doing a 'watch me do this' demo has been shown (can't give you a reference, sorry, and you'll just have to believe me!) to result in an ineffective transmission of the information - that is, people recall it inaccurately. This is why it is not safe, and why it differs from other aspects of antenatal education, which are not expecting you to remember a whole load of instructions just from seeing someone do it.
In addition, common sense shows us that demo'ing a sequence of actions several weeks, if not months, before someone is expected to do it for themselves is not going to be a sure way of knowing the watchers are going to retain this complex knowledge.