I haven't decided for definite yet, but I'm leaning towards "yes". I still have a few PS4 games that I haven't played yet. Those, along with whatever PS5 launch titles are worth picking up, will give me plenty to play over the Christmas break. Means I can sell my Pro now while it has a little more value.
I haven't even played a single PS4 game (been away from gaming properly for a long time) but this is also my strategy. Instead of using the PS4 slim now, sell to use as funds for PS5 and enjoy the old titles on there.