They're not like dogs and cats who can live together casually and play together but not be super bonded
While I think this is true for the most part, this is exactly what my boys are doing. They are bonded to the point where they have out-time together and they get along. But Ive tried the cohabitation and it causes way too much stress on Stormy. He becomes incredibly aggressive and because hes a senior, I dont want to stress him out.
But I definitely agree with whats been said. There is a good chance your pair would never accept another bunny. I have 3 bunnies and my female, Olivia, is the type of bunny who could probably never bond with another. She becomes super aggressive around other rabbits. You never know what their personality will be when you bring them home, especially a baby.