There's no inflation in the token model. You buy a subscription token for real money, then sell that token for gil in game to someone else. That someone else gets to pay for the game with in game currency, but SE still gets the money from the original purchaser, and the original purchaser gets their gil.
This only works if the game has an infinite free trial/non-premium status though. You can't exchange tokens and activate the account without logging into a free account.
Anyway, there are enough threads of the doomsdayers saying it would destroy the game because they haven't seen how successful it is in other games without being P2W (unless you think WoW is P2W). Better not to beat this dead horse again.