As someone that lives in Atlanta, this is one of those things that is so obviously not true that it's not worth spending the time to point out the flaws in the study.
It's not an anecdote. It's a basic understanding of traffic in Atlanta, the geographic limits of the ban, and all the Covid related fall out happening at the same time. It's the equivalent of arguing that days are 10% longer due to the scooter ban. It doesn't need critical examination to know it's wrong.
Atlanta is huge. It can take two hours at highway speeds to get through it. Most routes do not allow for scooters. I think it's obvious that banning scooters cannot have had impact on most commute routes. This conclusion needs to be more specific about commute routes impacted to help folks learn from the data.
I think they also need to discuss other projects which impacted commute times at the time. For example, major work on the GA400/I285 intersection began at that time. Changes to I75 and its dedicated pay lanes was underway. Those two routes are used by huge numbers of commuters every day and the impact was huge.
Atlanta has inadequate infrastructure that causes "rush hour traffic" on a tuesday drive on the highway at 2:00 pm. The city is not 21st century compatible if "value for time" is important.
I supported two offices in Smyrna and Buckhead for a few years and lived in Gwinnett initially and relocated to buckhead after. I-285 sucked both ways in Gwinnett, but in buckhead, i was going against traffic, which made a friday commute in the rain a 15 minute drive home in buckhead. The logistics are much worse now.
I did happen to be in SoCal when the pandemic started and got to enjoy their highways with little to no traffic. I think I was only in like 3 or 4 traffic jams the whole time, when Atlanta is a traffic jam mon-fri from 7am to 6pm'ish.
When visiting Portland, the commute south mon-fri was always backed up during rush hour times (just like the good ole days), going towards Salem. Inadequate infrastructure from the 20th century makes some cities worse I guess.