Mommies of Multiples: Bedroom Arrangement

We are ttc our second and I think we may have succeeded. Our son is 6 months so they will be close in age. We never bought a crib for him, just kept him in the pack n play when he would use it but he would mostly sleep with me. We've been sleep training and since we are ttc we bought a crib for his room and are transitioning him. My question is: when the second baby gets here should they share a room or should I ready the spare room for the new baby. I know it's a good ways away but I wanna get this planned out now. Pretty sure it'll be a boy as my husband is 1 of 3 boys and his dad was 1 of 8 siblings and only 1 was a girl. Our house is 3 bedroom so does having them share a room from the start make better sense or have them separate and then move them together later if need be: I.E. we have company overnight or have a girl later on?