Downsides are ;
-more received traffic on the multicom
That was exactly the problem on day one of one of the previous changes.
I
think it was when CTAFs were introduced, and they were all on 126.7. Requests were made immediately for various locations to have a discrete frequency allocated to get around the problem of excessive comms, confusion re RWY vs. location etc. etc. and that has continued ever since.
Some people seem to think that there are simple solutions to problems, not realising the complexity.