FF13-3 is no way a sequel to FF13 in anything other than story. Looking at the video its not the same battle system , they may claim it is but it isnt.
FF13 was like a fast paced version of FF7 ATB which allows queuing of multiple commands and that some commands have higher usage cost (multiple ATB bars). With AI controlled allies.
It was certianly a shock to the system for turn based fans as myself however after I got used to the game it was still a good game. Also surprisingly not much bugs considering how bad square are at releasing games with bugs.
FF13-2 copied FF13's battle system so a sequel but in my opinion a not as good game, down to 2 party members from 6 with a monster assisting, FMV's significantly reduced replaced with cheaper to make in game sequences. Areas copied for low cost production. Game balance completely messed up (way too easy compared to FF13 which was balanced very well.)
Now here is the thing, some may not admit this. FF7 is a good game, however it suffers from a flaw which is common in many jrpg's which is it has many near useless abilities, how often in FF7 do you bother to confuse, sleep, slow enemies etc. Or do you just hit with your hardest hit attack repeatedly to get through fights, eg. 4x cut, ultima, kotr. FF13 is the first jrpg I played in a long time where spamming attack is not efficient. You have to utilise enemy weaknesses to efficently kill them and boss fights were genuinly diffilcult without having to nerf yourself. Of course it seems many casual people complained and FF13-2 reverted to type, so enemies with low HP counts and basically spamming attack works much better in FF13-2 than in FF13, but FF13-2 is still a reasonable game.
Funny enough I am not a big fan of FF10, I think that has a bad level up system (having to use all characters every battle if want to give them exp), also no normal stat increases.
The tales games in my opinion (as well as star ocean games) do not compare to FF13-3, the tales games still feel like a jrpg (action based jrpg) as you have a party still and not zoomed in. Lightning returns FF13-3 looks like a action game with rpg elements, it seems square no longer want to be a jrpg developer. Instead going for outstanding visuals and action to please western casual gamers. Withn 5 years it will be first person view for a FF game.
Turn based games can still work, think of lost oddysey, absolutely brilliant game. The problem is now days profit is king, making a game that appeals to the masses is more interesting to publishers than making a great playing game for a niche market.
A remake of FF7 which has hard, ultra hard modes and a new game+ would be fantastic. But it wont come.