If they wanted to do this, it could be another project, you know. They wouldn't have to drop FFXI. They wouldn't have to drop FFXIV. They could actually even call the game FFXI-2... hell, they've done it for FFX and FFXIII now, so why not FFXI? The company is huge and has many dev teams, so it would be quite possible to make it parallel.

Now that being said, would I play it? Probably not. And here's the reason.

I would only play it if it could be released before FFXIV gets "fixed". Which just wouldn't happen. FFXIV is already on track to become a great game, and it couldn't possibly take them as long to fix it as it would to make FFXI-2.

Also, from a business standpoint, it wouldn't make any sense. At that point, they'd basically be giving up on FFXIV and would be better off canceling it altogether to make a FFXI-2. And I guarantee you there are a lot of players that wouldn't want that.