So who cares if Snoke is not his real name or he came from the unknown regions and he’s not the only threat out there; that doesn’t set up anything because this is the end.
Presumably there won’t be an Episode X, XI and XII at all and definitely not in the near future.
If this were the middle chapter in the trilogy, the answer might offer clues about what is to come, but it’s not.
Beyond just a bit of fan service, the only reason to tell audiences about Snoke from a story perspective is if the answer serves some purpose and still matters even after his death.