apparently the level jumping potions that are going to be released in the near future (date unknown for NA), are able to skip the whole 2.1-255 quest chain and marking the level 50 dungeons and MSQ as completed/cleared. At one point, there was a discussion about MSQ only skipping potions, without the boost of character levels. It's defiantly not planned as a part of the regular expansion or be included in that. It will most likely be something you need to buy via Mog Station, if both potions or single potions, are even made available to NA players. Just have to wait and see if some of the upcoming live letters or interviews will give us some more information.