This was supposedly added a while back but I cannot for the life of me figure out where it's supposed to be enabled.

The API for it doesn’t exist in Classic so the indicator was removed for that version. I believe there was a library for it in the past so it may be possible to bring it back.

According to https://github.com/Ketho/BlizzardInterfaceResources/blob/classic/Resources/Events.lua#L742 it should be, but yeah, the only reason I suspect is because the event is working for some other addons I use

Edit: It seems this already happens?

UnitHasIncomingResurrection is available to the classic client no? As for summon C_IncomingSummon.HasIncomingSummon might not be since it's pretty new

It exists yes, but who knows if it's hooked up to something 😝 If someone can test if the event INCOMING_RESURRECT_CHANGED actually fires (eg, the icon shows for casts on the blizzard compact raid frames), that would be an easy fix.

live vs classic :p