Modern FFXI is not really that similar to FFXIV. Yes, it's a far cry from the way it used to be, but let's not go crazy here. It's just that some of the harshest edges have been rounded off by now.
I see people wishing for pre-Abyssea servers fairly often, and I just don't think it would work. Yeah, a lot of people say they'd resub for that, but how long would that actually last? I think what people really want is the sense of community that the older FFXI iterations, and that's surely not coming back, even if they make old-style servers. Ultimately, pre-abyssea FFXI is a game that I don't think can exist in the modern MMO world.