Years ago, pre DC, I remember my SIL telling me she was upset she couldn't go to the wedding of a good friend, because it was childfree and she was still feeding DN.
I nodded along but didn't really get it. Having never breastfed myself, and not knowing lots of close friends who did, I had no idea that some babies can't take a bottle, that breast pumps don't work for everyone, that it's not quite that easy just to leave a breastfed baby with a sitter, that engorged boobs are painful and can leak.
Giving the OP the benefit of the doubt, I think that her post is founded on ignorance, and she's not just being a precious bridezilla for the sake of it.
She honestly can't see that the option presented to her - ie family members bringing the baby for feeds every few hours - is the easiest and least stressful option, which also probably means going to a lot of bother for the sitters.
No baby at the wedding, no leaky boobs, no baby going without feeds - it's win win for everyone but the babysitter, right? As OP can't see that, I can only imagine she has v little idea as to what bfing actually involves.
And why would she, if she's never done it? A bit more empathy wouldn't go amiss.