It's called astroturfing, and it's standard PR and party politics. The idea that a mainstream newspaper, which is beholden to advertisers and granting agencies could be dismissed as "right wing," is ridiculous. You may in fact believe the National Post is edgy, and that a literal newspaper is still capable of offending delicate sensibilities, but I can't accept that view as worthy, serious, or normal.
I think you misinterpreted my comment. Calling the National Post "ring wing" is not some kind of slur. I would similarly call the Toronto Star "left wing". They all have their leanings, that's all.
This is kind of an interesting misalignment, where typically one would use conservative vs. progressive, whereas the -wing generally implies a specific critical viewpoint predicated on polarization.