I too would have liked to see new faces instead of bringing back the old guard. Call me a loon but I almost feel that Obsidian went with the returning companions idea (and by proxy the Watcher as the protagonist), just beacuse Baldur's Gate 2 did it. The thing with returning companions is that they are usually universal fan favourites. If you look at BG2: Jaheira, Minsc, Edwin, Viconia and Imoen - all of those characters were really popular back in the day - even Imoen (hell, *especially* Imoen). The same goes for Mass Effect (Garrus, Tali) and KoTOR (HK-47 and Canderous/Mandalore).
In PoE franchise, the closest thing to a universal fan-favourite is... Eder. I guess a lot of people remembered Durance, but he was definately a hard sell for many. Avellone's departure didn't help things.
Pallegina was popular in some circles, but she most definately wasn't a breakout character, with majority accusing her of being bland and unlikeable. Her coming to Deadfire has narrative sense, sure, but in whole honesty, Obsidian could've created another VTC faction representative from scratch and not much would've changed - at least for me. Deadfire Pallegina is a much different beast to the Pallegina we knew from PoE 1, anyway.
Aloth was always "along for the ride" for me - I liked him, but he kinda lacked presence in PoE 1. Yes, I know that's the point of his character, but still. Embarassingly enough - and a lot of people will probably want to kill me for that - I kinda kept forgetting he was supposed to be in Deadfire. Imagine my surprise on the dig site. Anyway - unlike Eder's or even Pallegina's, his story arc was done and wrapped up by the end of PoE 1. He succesfully dealt with both Iselmyr and his allegiance to Leaden Key and there was nothing more to tell. Why insistance of bringing him back? Was he really that iconic?
But to be honest, aside from maybe Eder I was never particularly invested emotionally in any of the returning companions, so I kind of felt that we are wasting a companion slot that could've been used more efficiently. But that's probably a problem with me.
And lastly, real talk: Obsidian - don't be afraid to create more quirky and unique companions in the future. I don't think that constantly coming up with those down-to-earth, world-weary characters makes this franchise truly stand out.