I believe they can fit all species, provided they are not all breeding programs. One Okapi can be held off display, therefore opening 2 elephant paddocks for rhinos. Bongo would be where the tapir and peccary are now, and tapir of course on the barn. Mandrill reclaim the old exhibit. Potentially the okapi could be rotated between themselves and the bongo in both exhibits. Wishful thinking and chances this happens are low, but there is certainly enough space for them all imo
I would've thought that if the zoo was going to bring in either Indian rhino or okapi then they would want to be breeding them. Both species are simply too important to not try to breed. The effort and cost it would take to acquire either wouldn't be worth it if breeding was not the intention.
I would assume that if either of these species come to MZ then MZ will be hell bent on breeding them. I'd be surprised if they weren't.