I don’t think Zeliek is a good example of why Undead Paladins should be a thing. He is the exception not the rule.
But my point was more that Blizzard are very inconsistent with the lore. They change their mind on… everything, on a yearly basis. Remember when Elune was hinted at being a Light lord or possible the creator of the entire setting? And then she turned out to be the Winter Queen’s sister, and even that is suspect now.
Either way. If Blizzard want Undead Paladins to be a thing they are going to use the new “Lightforged Undead” (just the fact those exist should tell you how much Blizzard care about the lore) rather than the old Lich king created Forsaken undead.