Well, that's not the reality at all. Neither new ride in Pandora was a coaster. TSL is adding one coaster and one flat ride. SWL is adding two rides and neither is a coaster. Epcot is adding a GotG coaster and a UK non-coaster. And the MK is getting a TRON coaster.
So, with the two rides going away, only one replacement will be come a coaster. Of all the new rides, only 2 of the 8 are coaster. That's a total of 3 out of 10 rides. That is not "a disproportionate number of coasters."
So, the reality is that your statement is false.