May contain TWW spoilers.
We know this will happen, but we still don’t know when, but story clues have been here, and they have been for a while, and here is my prediction of time period and the story bits for both.
For shamans, the elements to being them to all the remaining races has been not as present, but there has been some effort. We see that some primalists have got to our side, and have been kept on custody by night elves in Bel’ameth, we also see a couple of druids of the flame that also joined our side, this not only brings the oportunity for night elf shamans, but also other races, as the primalists were not Nelf only. The new black dragon aspect is Ebyssian, that as ebonhorn is also a competent shaman, and the earth warder role was also given to Thrall at one point, Ebyssian is also a friend of the horde, so i think this connection could be used. With that said, I have a prediction, this is pure guess work and wishful thinking, but, I think I may have hit an element or two of this.
Thrall is the final component for the shaman patch. He will regain his connection with the elements, and it will be in a shaman quest, where the shaman player will give him the doomhammer back, just like Warlocks had a questline to “celebrate” other races getting warlocks, I think this will happen for shaman players. In said questline we will meet several new Shamans that will have lines explaining hpw they connected with the elements, and maybe, if Blizzard is feeling fancy, at the end of the questline you get more options for the ghost wolf form or totem customization.
For paladins for all races, there is a more solid foundation being built, in dragonflight we stablish a new order of multicultural paladins that will help Tyr see the new world and things, we also have in TWW the Arathi, that seem to have a strong connection with the light. We also saw recently a Void elf paladin npc, arguably the hardest race to argue for paladins has been made available in lore. And, like shamans, herenis my prediction.
Like thrall, the questline that will serve as gateway for paladins for all races will have Anduin as a key element, Anduin was never a paladin, but a priest, physical fighting was never his main attribute, he also wielded shadow as well, he was not a fighter, but people change, times change, for years now Anduin has been living by himself, as a wanderer, doing manual labor, and has become a competent fighter, but his connection with the light has been lost, and the void will tempt him, so, I think it will be a point of the story where he will have to make a call, and that call will be to embrace the light again, but this time will be as a paladin and then we will have a questline with him, the Arathi and the tyr’s guard, focusing on the light, and showing the new paladin npcs.
My prediction of when this will happen, to me, everything points towards 11.0.5 or 11.1 for that, after the first raid, Xal’atath will probably become more present, we will be introduced to the future content, and I think it will be the right time.