FF definitely hasn't been as iconic since FFX, although XII was very good. They used to be system sellers - I bought my PS3 in part out of anticipation for FFXIII - but that game was so lukewarm that the series never recovered it's status. XIII was a good RPG, but not a good FF.
It's nice to see XV being successful and people excited about the series again. I do give S-E credit for trying to make each game unique, and although I love Dragon Quest, the series does start to have a sense of been-there, done-that since the basic aesthetic and mechanics never really changes. Bright green fields, the same enemies, etc. Still charming, though.
Honestly that opening was one of the strongest moments of the game for me, which probably isn't the best takeaway. The best thing it has going for it is the friendship stuff and even that is kind of marred by the weird pacing of the game, and virtually all other side characters being being criminally under utilized and not fleshed out enough, not to mention the main party's relationships only really being great if you watched the Brotherhood anime.
I think if you buy specifically just the Royal upgrade, you don't get the character focused DLCs. That's only if it includes the first Season Pass. The Royal upgrade had a bunch of changes, but I think the main thing you're paying for is a vastly expanded ending, which includes a lot more story stuff and turns the final area into a real dungeon like it always should have been.
If you buy the Royal Edition of the game, it includes all currently release DLC, but not the upcoming Season 2.
Re: the Royal "upgrade" online, this is correct - it doesn't include the season pass. From the store listing:
It's nice they have an option for folks who already own everything else to get the extra content, but it's a tad misleading since the full 'royal edition' includes the season pass, which for $25 on sale, is a great deal. I put 60 hours into the base game at launch and really enjoyed it for the most part.
I don't think the season pass has been on sale in a long time since they are pushing the royal edition now.