You must live under a rock if u dont know the basic business antics that ALL modern blizzard games deploy... New product is shiny and OP to get people to purchase it. Get sales mission accomplished, then nerf it immediately after money has been taken.
If u gotta look specifically at any of acti-blizz's "modern" diablo franchises ... date it back to D3 ... necro package release made THE BEST Exp farm class (Rat Necs) that lasted like for 8 years before they finally decided to Delete that build from existance lol... Crusader was like a top tier RGK boss killer for groups so if u didnt have one, ur team sucked... Then look at D4 ... Spirit born was THE only class to clear the first Pit 150 when it was released (cause Bugs ofc but that was intentially done to get sales done)... Then class was nerfed after maybe 3 ladder seasons BUT money was taken and made. Cant give no refunds by that time right???. Then Pally was just released like a few months back ... it was THE BEST class for that duration. Again only class to the the highest clearing cotent lol. Then they nerfed it after its first season but its still the strongest class currently. And they will do the same with their D4 warlock. Gonna be the busted class to maintain sales till once the products have been sold will they nerf it later. So what made you think D2R warlock would get a different treatment
regardless... ROTW made its money for the QOL stash stacking feature (i dont need to make a billion "spirit rune mules, Mid rune mule, crafting mat mule, etc" anymore) and that SUPER basic 3rd grade level loot filter... that alone is already good enough even if they bring warlock back to same power lvl as other classes. Besides theres zero reason to ever go back to Expansion mode anyway because theres NO -% resistance on those sunders and all the new magic pierce items in ROTW that isnt available on Expansion (so Hammer-man and Necro are the big winners here. Just masked behind the current OP warlock thats going back to earth after the new patch goes live when reset happens...)