I agree it is normal if the app was opened but it was not. My setting for “On screen wake show last app” was set to ”While In Session” yet closing, display still comes back on wrist raise. I had never launched the app since the upgrade and even force closed it. Still it comes back on wrist raise without invoking the stopwatch app. It is definitely a bug related to the upgrade.
I had restarted the watch which did not resolve. I have unpaired and paired new with restoring to a backup. So far, this is working now as expected without displaying the stopwatch app unexpectedly.