It would be nice to see Louise Jameson in a cameo on DW. I've heard she did some Big Finish work.
Well you never know! That's the great thing about Doctor Who. :)

Speaking of Missy, I only just watched "Spyfall". Yeah, I'm late and only watching what I've been told are the essential episodes.
*claps* That is probably my favourite of all of Chibnall's run (so far). A few, um, questionable choices, but overall great fun. And Sacha Dhawan is *chef's kiss*