If they'd internalized the lessons of the last ~10 years, Geoff, Matt, Jack, Gavin, and Michael, and maybe Barbara and Kerri or Miles, would have done the farewell stream, explaining the circumstances, and that would have been that. These are the faces people remember from before RT went to complete shit.
If I had to make a "perfect goodbye" lineup, I'd say have Gus, Geoff, Matt, Gavin, and Barb as the "main group", for the following reasons:
Gus, Geoff, Matt: Of the original 2003 team, they're the only ones that lasted the entire run of the company.
Gavin & Barb: These two were the first "community hires", and arguably the last good ones. According to Burnie on some of the earlier podcasts, the two of them basically grew up as part of the Rooster Teeth team.
From what I saw in the 2009-2019 era of things, those 5 actually had decent chemistry and bonds with one another that extended beyond workplace niceties. Furthermore, given their positions within the company and the ways that they worked their way into said positions, I feel like they'd have the most to say that's relevant to the overall decline of things.
Outside of that main group, I'd say add Jack, Kerri, Michael, and Miles as a rotating lineup that would swap in and go over stuff from their eras within the company. I'd also say maybe add the Diaz twins too, since they seem to be the last members of the AH staff that didn't suck, but they came after I stopped watching the RT network so maybe I'm wrong there.
Have the stream run maybe twice as long as a typical RT/Off-Topic podcast episode, give all of these people their opportunities to talk about the good and the bad of the company from their perspectives and without the filter of Warner Bros keeping the discussion brand-friendly.
All I hope is that everyone there realizes that this is his or her fault in particular. It wasn't out of their hands; they fucked it up personally.
Every major channel eventually fades into obscurity or runs out of relevance in the public sphere. It happens, and there's nothing you can do to stop that. With Rooster Teeth, though, they killed their own momentum with diversity hires and over-extending themselves. Maybe some of this was the fault of WB, maybe a lot of it was WB's fault, but chances are RT had more power to fight back against the changes while they still had the support and respect of their community.