1) XV is not going to age well. The game is still pretty new but I fully expect a XIII-like turn by next year. It will be a banner title for "how not to make a game."
A XIII-like reception turn isn't even
possible for XV. The reason XIII's reception soured the way it did is because the game's initial release was carried by the series' high reputation and the excitement of the first next-gen, fully HD FF experience. XV was releasing off a 10-year limbo and off the heels of the lowest received mainline FF games in history.
Can't see the game itself aging that fast either, for multiple reasons. First off, the game is still promised significant content updates, as well as story enhancements. PS4 Pro still has room for further improvements. We've just seen first images of what could be a PC release. The game is getting
better as it ages. And as far as its tech and visuals go, it's one of the most impressive titles on console, and will likely be one of the most impressive on PC as well.
2) SNES-PSX era FF pushed the genre forward and innovated within the medium. FFXV does not push the genre forward, it just copies the same AAA formula of Western games and shoehorns it sloppily into a Japanese design sensibility. Long after everyone is talking about Open World Fatigue/Ubisoft Syndrome FF decides to jump on the bandwagon by giving us something every other game is giving us. Hooray? Different for FF is not necessarily different for video games.
Personally, I don't really turn to JRPGs for Western design tropes.
What you perceive as "western" about XV is its sense of scale and heavy application of technology. But to any actual western RPG player, XV is still
very obviously a JRPG. You'd be hard pressed to find a review of the game that isn't still making the same boy band jokes from Versus XIII's era. XV's gameplay is just as unique now compared to current WRPGs as it was back during the PSX era. Yes, the game has cars, quest markers, large maps and dialogue choices. But it also has extravagant visual effects, warpstriking, aerial combat, summons, gag encounters, ridiculous hairstyles...you know, the type of over-the-top exaggeration that got most people into JP games in the first place.
Say what you will about its direction...but there isn't
anything standard, normal or common about Final Fantasy XV. There is no shortage of reviews or previews of XV that don't mention the game's "heart" or confidence in its unorthodox direction.
What XV does add to the formula is a worse version of what SE has already given us in Kingdom Hearts. I personally found controlling the camera to be more challenging than any of the fights. Story-wise, the game is an impenetrable disaster. The graphics are pretty. They will age, too. Then what?
Well, you can say that of any game, i don't see how it's a special case for FFXV. FFXV's achievements (for Final Fantasy as a series) potentially go way beyond FFXV itself. The team is experimenting with expanding the series in directions it was unable to travel in before XV came along with its new direction. Whether you want to call it "western" or "directionless" or whatever is just subjective to you. But on paper, it's very easy to see how XV is a good thing for the series.
The way I see it?...Square Enix has been pursuing "Advent Children: The Game" forever now. They've even admitted this on multiple occasions. And XV is the first and only time since that goal was mentioned that it has become a feasible reality, in visuals, scale and gameplay. XVI can either continue in the same direction as XV, using it as a learning experience, and deliver something truly spectacular...or Square can succumb to the nostalgic fans and start backpedaling again.
Luckly (for me), Square has made it clear on many occasions recently that they have no intention of backpedaling just for the sake of nostalgia, tradition, or whiny fans. If they did, XV would have been a very different title. Final Fantasy has
never been that type of series, and i'm still an FF fan because it refuses to be.