What I think would be a really awesome next step is to have the kids who have their wish at Blizzard to have a version of themselves put into the game, either as quest givers, NPCs in hubs or even as supporting hero NPCs in dungeons/raids. That way as long as WoW lives, so do their gaming spirits.
Even better than that, Blizzard could go on to have versions of them in all their games, as monuments to legendary heroes, or as characters of historical importance in the lore. It would be a wonderful way to thank them for their interest and dedication despite medical conditions that otherwise try take everything away from them.