The transwarp hub would be abandoned due to all the problems the Borg are having, 8472, unimatrix zero and I'm sure there was another major one, so they just up and leave. Meanwhile the Talaxians come in and take over. Sure you could find problems with this but I think it would still play better than the ending and not have one of the main stars leaving so close to the end but yet so far. Plus it would have kept the Borg out for the most part with just their tech on show.