It's honestly a weird classification. At lot of that talk took place during Bill Clinton's impeachment and the event of him having sexual relations with Monica Lewinsky. i think sex can be defined slightly differently for everyone.
For me personally, I consider losing your virginity as putting your dick into a vagina or getting some dick put in your vagina. I've never had any sexual relations with anyone at all so I would consider myself to be an Incel Virgin but even if I got a blowjob, I think I wouldn't be considered an Incel but maybe I'd still consider myself a virgin, just not to the large extent that I'm at right now.
I may be based here but that;s just my view on things that will never happen to me.