I see 'pay-to-win' as being able to 'pay-to-win'. Like pressing a button and bein given something you typically might have to work towards in some way. P2W has long since been pushed back in definition by many just to mean 'gaining a competetive advantage over others' but really that could be considered a side effect of something that might seem benign, but really is paying to win.
If you allow buying gil then you are absolutely making your game pay to win.
My example: I recently came back to the game after being away for a few months (I wanted a peek at Eureka). Deciding I didn't like Eureka, I went to go get geared and see about end game raiding. I asked what the fastest way to gear was and many suggested buying gear off the marketboard, but holy crap those prices. I could not afford to buy that gear.
Now if I could buy gil from SE through 'any' means (token subs as an example), then I could absolutely pay my way to victory.
And while many will justify this as 'pay to not grind', that is sort of an irrelevant term since by paying real money I could essentially be considered to have sat down and pressed an 'I win' button a number of times until I had sufficient gil.
And again, many will say this is not 'pay-to-win', but this is an MMO where the game is a non-literal theme park. Being able to pay real money to skip a step gives you an advantage.
Now I have no idea if OP is serious, stirring the pot or being facetious, but this would destroy the game. I'm leaning towards stirring the pot since I like to give people the benefit of the doubt.