Going off realmpop numbers here,
Prior to connected realms there were 26 realms out of 246 in the US which had over 100'000 characters. There are now 95 servers you can connect to with over 100'000 characters on them.
There are 95 Normal PvP realms in the US (BR/LA/OC excluded), 27 have yet to be connected to another realm. Of those 27, 12 are too high population to be connected and 9 will be connected to at least one other realm in the next 3 weeks.
I don't see why it would be better to 'merge' them. The insanely low-pop realms are gone for the US. There's a few which will be around for up to 6 weeks at this rate, but after that it's all done.
The only non-high pop, non-connected US PvP normal realms which haven't been mentioned for connection are :
We're already at the point where half the 246 realms in the Americas and Oceanic region are connected to at least one other realm.