That's about the size of it. Oddly enough, whether police can collect DNA from arrestees was the main legal issue in a moot court competition that I participated in some years back. The Supreme Court eventually took up that issue (in case originating in Maryland) and found that a DNA swab at the time of arrest was constitutional (see here for a summary: https://www.oyez.org/cases/2012/12-207).

It's not clear to me from the original article here whether France's system requires an actual arrest before they can demand that a person give DNA.