Source & EV yields Gen 3-4
EV yields Gens 5-6
EV yields Gens 7
That article has a list, too.
Pokemon that had yields changed in Gen 5: Ninetales, Shaymin Sky Forme(B)
Pokemon that had their yields changed in Gen 7: Alolan Ninetails(D), Alolan Dugtrio(D), Aegislash(C)
A lot less than I expected. I also included what I found about exp (because base exp has changed a lot) mostly because it was also listed with EV yield.
I noticed that almost all the exp changed in Gen 5 more than other gens. Also, in Gen 7, megas/primals/Hoopa Unbound give more exp than their other forms.
I had to go down the whole lists manually :(
(A) Note that EVs didn't exist in the first two games, because they hadn't developed "Birch's Theorem", as the community calls it, but they did exist in the remakes (Leaf Green, Fire Red, Heart Gold, Soul Silver).
(B) Sky Forme now gives 3 Spe instead of 3 HP.
(C) Blade Forme now gives 2 Atk, 1 Sp. Atk instead of 2Def, 1 Sp. Def.
(D) All other Alolan forms give the same EV yield as their Kanto forms.