Some Mega evolutions have gotten smaller as well
Mewtwo goes from 6'7 feet to 4'11 when it mega evolves into mewtwo y
Alakazam goes from 4'11 feet to 3'11 feet when it mega evolves
Gengar goes from 4'11 feet to 4'7 feet when it mega evolves
And it appears that Mega Salamence has gotten a bit smaller as well.
I will edit more in later
When Dragonair evolves into Dragonite, it goes from 13'1 feet to 7'3 feet.
Gloom (2,7") to Bellosom(1,4") is the only one that gets smaller on evolving
Thanks Shift :)
Hope I helped!(for now)
There are four. Dragonite, Bellossom, Porygon 2 and Gengar.
commented 4 minutes ago by Crimson1
Didn't know about Gengar and Porygon2. Thanks Crimson!