Problem still happens where Unity’s splash is covering up the dialog box for upgrading scripts, or errors. You only notice if you check the task bar.
Then, in task bar can switch to the hidden dialog box.
1440p resolution if it matters, on Windows 11. Alpha 18 and below.
I’ve noticed this as well - the other day, half an hour later it still hadn’t finished, then realized it still hadn’t even started when after clicking on it in the taskbar the dialog appeared (presumably as you said from being hidden under the splash).
Easy repro for this: Make a project using any older Unity version. Open this project on a18 and note how you get hidden project upgrade prompt.
This has been broken for a while in the recent alphas (maybe as long as the new style loading screen has been there?)
Hi! Just wanted to let you know that the fix is in progress and should be ready to land soon.
Then you just improved loading times by 30 minutes for some people! That’s outstanding 
Fixed in 2022.2.0b5 