I don't personally find it helpful to term political correctness - aka New Leftism, the faith of Social Justic Warriors - a religion. But if we do this, and decide to designate PC a religion - what kind of a religion is PC?
PC is a religion in the same sense, a limited sense, that devil worship is a religion; which is to say PC is not a coherent world view nor a prescribed way of
life; instead PC (like demonism) is a project for piecemeal, incremental destruction: over time, strategically, it entails destruction of that which is good (virtue, beauty, truth).
PC is therefore not a religion like other religions - not one religion among many choices: it is unique. All other religions are partial truths; but PC is not a partial truth.
Of course, at any given time point PC has truthful aspects or else it could not survive and thrive - but as a long term project all of these truths are susceptible to subversion, denial and inversion. Over time, sooner or later, by rotation; all values are marked for be destruction.
Therefore in its essence political correctness is a completely false religion; a religion that has not one single grain of truth.
(To put it another way: PC is the only religion that denies the reality of truth - but even this nihilism is not a core proposition, but simply what it does in practice: a motivation, feeling and trend.)