What content (Vehicles, people, stories, ect...) do you want to be added back to cannon from legends and why? I want The Old republic era to come back, because of how much stuff went on and all the interesting characters like Revan and his storyline, and the fight against the eternal empire.
But those are only a few of the reasons I want the TOR area to be brought back, but I want to see your opinion.

As far as I know, TOR was already brought back. A recent episode of rebels had Kanan mention the Mandalorian Wars. On top of that, they brought back Thrawn — which is pretty fuckin rad if you ask me.

As for stories I'd like to see return to canon, I'd have to say that Shadows of The Empire and SW Infinities RoTJ.

Yeah Thrawn is awsome lets just hope he doesn't die to early or die a unsatisfying death. And I actually haven't read Shadows of The Empire yet but I will probably read them soon.