A sync buff wouldn't be nearly enough for most players to figure out those old raid mechanics.
They'd need to revamp the whole raid series completely (not just a bit of tweaking) and add an easy mode, similar to the other raids.
I think it would be cool and rewarding for those who beat ARR, to be able to experience some raid boss fights. Totally agree with that. (and I would actually like to have to face some of those bosses sometimes in my raid roulette, not gonna lie)
But it sounds like a lot of development effort, for something that would really not be that useful.

Honestly, a simpler solution would just be to make it mandatory for the level 90 MSQ or something like that, so players could just go unsynced and go through it easily solo.
Maybe it will be, so that, when we finally meet with Fourchenault (the twins' dad), we can explain him what truly happened to his father...
Actually, they could have added it as a requirement to the Wherlyt questline...or even for the first step of the Relic quest. Both of those are also somewhat related to the end of 1.0...