Yeaah - still do remember how they kind of ruined my initial happiness on Roy returning to Smash 4 back in the day - like the outcry was pretty huge, and had me feel like Smash-fans only played favorites whenever giving "congratulations" to newcomers or veterans (same for FE-fans).
However,I think what was more ____ was that I dug my own grave by the time I allowed haters to affect me that bad.
However, contrary to what you think, I don't think there'll be lies spread around to make Roy-detraction resurface the same way it did back in 2015. As far as I've witnessed over time, Roy's hatedom had actually started to dwindle down actively as there's been more fans finally clearing out the misconceptions about him since Smash 4 brought him back. Now the fandom mainly holds
indifference and mixed bag of hater minorities + fans who like him for certain reasons.
And much like
Seraphim.
had said, Roy's popularity keeps on being surprisingly high today, beating even the likes of more "better" fan-favorites according to the fandom (mainly Hector).
While one could be a lot due Smash Bros doing it's magic on adding to his overall popularity, it surprises me how Roy managed to beat Marth + PoR Ike + Robin on top spots, even if the former characters are being more amicable to by the FE Fandom (and arguably Smash-fandom since Brawl-days).
If the haters were right, I don't think Roy wouldn't have perform as ludicrously well as he did. That's nothing to sneeze at.
So I think his return wouldn't be necessarily be outcried against strongly like before, maybe instead being accepted in same vein as other semi-clones. Though that depends on if people think Roy either will take "spots" for more deserving FE-reps, or creates today's classic FE Overrepresentation-scenario.