1) You enter the game and you're immediately a geared "Hero" (you're already a "Hero" in lore anyway) and you are immediately geared to do anything currently in game including Sylvanas mythic (obviously: normal mode might have to be removed and some bosses might have to be buffed because of this and that is fine).
2) As a result: you focus mainly on PROGRESS and the true prestige in the game is who had the SKILL and determination and STRATEGY to be the fastest at dropping a boss and not who is also a no lifer that grinds all day.
3) Bonus PvP benefit: PvPers will be the happiest of all. Purely multiplayer games should have 0 gearing or grinding benefits because they are exclusively about fair competition between humans.