That's The Situation Room finishing up the weekend specials, apparently they only thought they'd do them for a few weeks but, well, news.
As for the other things, I think all domestic presenters are guilty of becoming more opinionated over the last few years. John King, Abby Phillip and people like Jim Sciutto are the most sensible/least dramatic. At the other end of the scale, the biggest ego by far is Chris Cuomo. I can't see him sticking around for long into a Biden presidency, tbh. He just wants to opine about "ReTrumplicans" (his witty word) night after night... ugh.
As for Don's announcement, pure speculation but they did have Laura Coates hosting the first hour of CNN Tonight back in November so maybe that's something to do with it? As it stands, domestic broadcasts from 4pm to midnight live Mon-Fri with only one hour hosted by a female anchor. Maybe they want to address that - the weekend political shows will have more permanent female hosting from next week.