The article does ask a good question on the sort of conundrum that could become an identity crisis thst fire emblem has rode itself into with the steady inclusion of social aspects in their games ever since Awakening.
Personally I would be in favor of keeping the model they developed in 3 houses while refining it further with the game mechanics they developed in engage. I'd also like to keep the whole marriage and matchmaker aspect that we saw in awakening and fates out unless they figure out how to tastefully weave it into the storyline.
And while it would take too much gamedev time to implement it, it would be interesting to whether or not its possible to blend and synergize the fire emblem strategy game aspect with some of the musou aspects they've been lately dabbling in. I'm thinking akin to how the Total War series handles army battles but making the choices of how to play each battle as being either classic turn-based tactical mode or going full musou hack'n'slash nonsense as options for gameplay.
I think for the latter bit you can either take a more d&d style for your turn-based combat or do whatever it is valkyria chronicles games do with their turn-based ww2 shooter movement and combat-wise