Hi Angela - I've just done the same and noted this slight difference from the last time I updated. As you say, no need to click on OK anymore or unplug for the update to take effect. Don't think it's part of 15.2 (that's a separate update), just a streamlining of the Wookie update process, which is quite welcome.
No unplugging is required? Thanks for the heads up, we used to need the reboot for the skin change to work properly, I'll check on a couple of builds and update our internal advice for other staff, ta. I've just been asking customers to reboot after the second progress bar completes. No reboot/hard close of Kodi being required will speed things up a bit.