I suspect it might do a lot for user retention.
Even on Julia 1.9, using Plots; display(scatter(rand(1_000))) still hangs for 7 seconds, much longer than it does in Python/R/Matlab.
(Source for timing: @nilshg’s great measurements here)
Having a spinner during those seven seconds, as stupid as it sounds, will make the wait more palatable indeed. And someone just trying out Julia will be less likely to immediately drop it again. (I have no hard data of course)