They didn't measure when work got done. They measured when people chose to update their project management software. That doesn't necessarily correlate in any way with when the work is actually getting done. So all of their conclusions are based on flawed assumptions and a bad data set.

Anecdotally, I am an active user of multiple project management platforms and do my best to keep them actively up to date. When I am in a state of flow and being productive I almost never break it to update the project management platform.

I'm honestly not sure there's much of a pattern to when it gets updated. Sometimes it's when I'm trying to get into a work mindset and remember what I did the day before. Sometimes it's when I'm winding down at the end of the day and making note of what I did. Sometimes it's in between tasks.

A better measure might be when git commits were made to repositories, but even that is a pretty imperfect measure. I often don't made small commits as a I work, but large ones once a cohesive portion of the task is complete (or several small ones as the same time using git add -p).