Doesn't matter what system they use, it will end up being the equivalent of gaining 10 levels. Even if there was some sort of skill tree, with the way the game currently is, you just gain points over time and, by the end of the story, you will have enough to max out the '8.0' tree.

I also do not see FFXIV going for more horizontal progression, the game is not setup in that way and, unless there is a massive shift in many aspects of the game, it isn't going to happen.

I, personally, have no issues with going past 100. At the end of the day, it is just a number.