Actually seems quite different from recent titles:
things not so needed but now gone -
class change re-grinding,
lack of avatar personality (seemingly, as they mentioned actually building cutscenes and story around them rather than making it all about other characters because changes of appearance meant avatars of awakening/etc couldn't be shown in cutscenes),
weapon durability to an extent (limited uses per battle before it becomes a nerfed version for rest of battle, tomes/staves are instead uses per battle spells)
things new or newish or returning that seems to be good -
branching paths with changes in plot that will/can happen (leaks even mention one or more of these paths have an entirely different plot within them that can be taken as a new path),
class system is free-form as anyone can learn any weapon just at different speeds and most things tied to classes in the past (skills, growths, weapon choice) are now tied to the character and what they learn
and the day to day activity stuff is like persona where you have days of the week where you teach and can choose or be recommended what to teach each student, and weekend you can spend limited activity points to train your own teaching skill or boost a student's motivation or spend extra tutoring session with a student or collect items or do a grind battle (normal mode always has at least one mission you can grind without using the limited activity points, hard always costs them). Your most important days are teaching, your days with the most choices on what to do are weekends - that way you dont lose out by choosing the wrong thing although what you do on weekends will help in different ways.
I'm buying it and will be playing it, everything i've seen so far gives the impression of moving in the right direction. and like krev, Radiant Dawn was such a strong title in the series for me that I have hopes for console FE now that one is here again - plus this is a multiple-stage class system rather than the standard 2-stage most games are so I might be too biased on that fact, but it's worth a chance either way.
There was nothing wrong with the classic Weapon durability system. They've been slowly modifying/removing mechanics that added depth to the challenge and this isn't a good step IMO.
I don't need an "Avatar". It's far more compelling to simply be in control of strong characters instead of making "safe" protags for the purpose of self-insertion. Look at Ike: hands down the most interesting Fe protag, and he was straight up a dick sometimes, but he had motivations and convictions that meant something. They haven't managed to do that since.
I really dislike the idea of open class systems. It's again catering to a different type of audience. The limitations of only certain characters having specific classes/weapons added to the depth of the challenge once again. Building your troop and sharing experience and resources with different people to fill holes in your strategy was huge. This open class system panders to people who just want to always use their favourite characters all the time, so their waifus can become whatever they need to perform well.
Persona stuff is cool, when well-executed. The reason Persona excels is because it has a limited cast of deep and compelling characters, something that has been non-existant since RD, (and was never a strong point in the series let's be honest). I'm not hopeful, but its got potential to be a good addition.
Honestly, I'm just gonna parrot the same opinions again. Radiant Dawn (excluding the support conversations being neutered) was the pinnacle of turn-based strategy RPG. The perfected a system in nearly every way, but it was unfortunately not a popular system.
Awakening "saved" the series by cutting the difficulty down to laughable with nearly unlimited EXP and resources, pandering to weebs with a self-insert protag and a marriage system, and making the cast of characters one-dimensional anime tropes.
A return to form would unfortunately give new fans whiplash, and ultimately be detrimental to the success of the series in the future. I just don't see how they'll ever realistically make an FE game that appeals to what I used to love about the franchise, so for that reason, I'm out.
All the best to Three Houses, I want to see it do well and for people to love it.
And maybe it'll surprise me and reel me in again. I hope so.