Thinking more about the Han Solo movie.
I'd bet on them having Jabba the Hutt in it. Then they'd also have Greedo and Boba Fett and a bunch of other beings who worked with Jabba.
Less likely but possible would be a cameo of young Luke and his aunt and uncle walking by the screen. Maybe Han needs to go to Toche Station on his way to Jabba and Uncle Owen happens to be buying power converters that day
Which brings something up... it's pretty funny Luke was hanging out around in towns publicly going by the name Skywalker the whole time. I suppose Vader told everyone there was nothing on that dumpy planet Tatooine to bother with so there was little to no empire presence until R2D2 landed there.