I would love to see another queen and while I am not overly fond of the newer movies plots and pacing; I don't care for keeping the designs 'pure' and exactly the same as the original designs despite being hugely into them. So a new queen, with a few different elements would be great to see and I feel like it would round off the new movies well and also feel strongly 20th will jab at Ridley to put one in for the attention it will bring in.
I suspect most of the new movie will be all about David and then shes just a side on that shows up, much like in Covenant.
As for an Alien King? Wouldn't mind seeing how they handle a beefy boy but doubt they will give us one.