This is a good point about data availability, and is certainly a caveat with the study. That said, I personally think legislation needs to be data driven, and when there's a lack of available data about a given topic, the absolute wrong answer is for politicians to gesticulate wildly and give into whatever moral panic happens to be sweeping through the constituency.

It's for this reason that I find that bills limiting minors on ebikes to be particularly pernicious.

Ate shit doing just under 30, but Ma's a nurse and had everything needed at home :p

I can't speak to the proportion of minors on acoustic bikes versus ebikes, but there are definitely under-18s with ebikes, in numbers ranging from "noticeable" to "common", if I may draw from anecdotes in my area and reports from around the country.

This is correct, although it may be for good reason: data for non-rider ebike injuries and deaths is not collected through the existing means, which focus mostly on motor vehicle collisions. The NHTSA's 2022 data report has this note:

Prior to 2022, motorized bicycles were collected as motor vehicles and classified as motorcycles in FARS and CRSS, and their operators and passengers were captured as motorists. Beginning in 2022, FARS and CRSS are no longer collecting motorized bicycles as motor vehicles. Consequently, operators and passengers of motorized bicycles will be captured as pedalcyclists when involved in a motor vehicle traffic crash. Any traffic crash involving only motorized bicycle(s) will no longer be captured in FARS or CRSS.

Essentially, the national data sources available today don't record bicycle-vs-bicycle or bicycle-vs-pedestrian injuries or fatalities. Some states or municipalities might record that data though. For example: NYC's 2021 data shows 2 pedestrian deaths from a bicycle collision, and 123 pedestrian deaths from a motor vehicle collision. But no data there on nonfatal pedestrian injuries caused by bicyclists.

A study looking at just a handful of municipalities would not be useful to draw larger conclusions. But seeing as the data collection at the national level was expressly designed to give insight into the most pressing injuries/fatalities category -- those involving motor vehicles -- I'm not holding by breath for expanded data collection, since bicycle-involves pedestrian collisions are at least an order of magnitude less of a problem than motor vehicle collision.