In other words, the foreground action setting off the notifications is probably a download. With some users receiving literally dozens of alerts to go along with the ones caused by Gboard, you might need to take some time clearing the notifications off of your screen since the “clear all” button might not be able to do the job. The bottom line though is that there is nothing to worry about if you do see the alerts on your screen.
App developers whose work is impacted by this change are being told by Google to use the WorkManager programming interface which is recommended for starting higher-priority background tasks.
Still, removing the notifications might rank on your nuisance list and depending on your personality, this might be considered a good reason to wait for the stable version of a beta release to be released before installing it, and that goes double if the handset in question is your daily driver. Frankly, though, this writer’s biggest concern preventing him from installing a beta version of an operating system is the drop in battery life often experienced while running a beta. Even with the amazing power banks available these days, no one wants to be forced to search for an outlet in the middle of the day.