The only reason anyone is "quibbling" over a word is because "concentration camp" invokes imagery that is not reflective of ordinary detention, refugee, prisons, or jails...including the boarder detention camps. If universally concentration camp only meant detention without trail, the disingenuous usage would not an issue.
Every attentive school child or minimally educated adult think that "concentration camps are where large numbers of people, especially political prisoners or members of persecuted minorities, are deliberately imprisoned in a relatively small area... to provide forced labor or to await mass execution." They associate it "with the several hundred camps established by the Nazis in Germany and occupied Europe in 1933–45, among the most infamous being Dachau, Belsen, and Auschwitz.". (Bing Definition).
To use that term directed to a general audience, while also attempting to link it to the "never again" phrase for rejecting another holocaust (AOC). is grossly ignorant of (and dishonors) history.
In short: no, the border centers are NOT concentration camps as generally understood in common discourse. AOC knew that and addressed a general audience using that term.