I acknowledge it was used within rightwing spaces, even that they had influence over its evolution. But your model implies "pilling" was ever wholly appropriated by rightwing culture, which would require it to have died out in other contexts. And I'm arguing it never did, that it maintained regular usage outside of that context and thus can't be assumed to be a rightwing signifier.

Even during the blip in time where specifically redpill was associated with manosphere pickup culture, bluepill's meaning evolved as the counter to it (for those that were exposed to the trend; both terms' general meanings never entirely vanished), and shortly after there was the ironic/postironic re-appropration of the new form of red pill. So even then one couldn't assume a person's ideology solely from usage of x-pill terminology.

But regardless of whether right-wing culture actually successfully appropriated the terminology a decade ago, it since has maintained widespread usage and evolved on its own in quasi-mainstream online spaces. So to claim the OP is mistakenly signaling some sort of incel ideology is questionable at best.

"Woke" is somewhat similar in that its common definition was renegotiated by rightwing appropriation. But in this case the word largely lost any original meaning as it became a floating signifier for rightwing rage. And even in this case, it'd need to be usage of the term as a pejorative to be considered rightwing signaling, usage of the term itself isn't necessarily so, per se (e.g. people reclaiming the word as pro-woke or using it ironically like dark-woke).