User blog comment:JaseyJasee/Why are characters from The Sims Universe and The Sims 4 Universe still together?/@comment-1519608-20150601020845

There was a discussion about this back when TS4 came out but the results were inconclusive, and as a result nothing really has been done to address this.

Given the problems with other ideas that have been put forward to solve this have their own drawbacks, the idea of split pages is a good one. There are a few issues to take into consideration, however. It's not quite as simple as laid out in this blog.