Rav Moshe in the Igros Moshe OC I 33 paskens that you can’t consider all non-frum Shabbos violators to be tinok shenishba since many of them have seen or heard about religious Jews or the Torah.
So, l’maaisa, if they know or heard about Orthodox Jews they are NOT a tinok shenishba.
The Pri Megadim in Eishel Avraham 325:22 discussed the possibility that a Shabbos violator might be treated as a gentile in some matters.