F droid builds a number of apps from sources on their own infra so it might be that a fdroid maintainer pushed and built updates for all the apps they are responsible for and you and that maintainer have a sizeable overlap in app preferences.

My guess: The apps aren't updated all at the same time, but the F-Droid client only checks for updates every so often, so you'll see them all at the same time unless you increase the check frequency.

How often do you even open the F-Droid app? I only do it about once a week to check for updates, and "every F-Droid app I installed has updated in the last 7 days" doesn't sound exceptional to me.