Currently (as of right now) XT is Bitcoin as it operates seamlessly with the bitcoin network.
No, the XT is
pretending to be Bitcoin, but it's not.
It is extending the current protocol in its consensus-enforcing part. Because it says: after 2016-something if 75% miners have done something, we can produce larger blocks. It implicitly states it can do something the current protocol doesn't allow, under certain conditions that you call 'consensus' (which is far from the real consensus). It can disguise as an ordinary client in the meantime, doesn't matter, it won't make it Bitcoin.
It's not like protocol will be changed only if 75% miners agree, it's already changed by adding this very condition. Protocol amounts to all consensus-critical rules, implicit and explicit, that are written in the software.
Is this a case of selective censorship?
You need to learn what censorship means.
I'll quote your beloved opponent in case you didn't read his reply to you:
Being moderated on a private forum is NOTHING like being suppressed by censorship. What a nasty, horrible lie! Why don't you just track down some
Chinese dissidents and shit on their faces? Either way the [trivializing, disrespectful] substance is the same.

What you gloss over as "imprecise use of the word censorship" isn't accidental or mere ignorance. It is a calculated attack on the mods' integrity (IE shaming), and a purposeful re-framing so as to paint them as victimizing brave supporters of free speech ("zomg it's a human right!!!").
As to their (and now your) "concern as being over the subreddit
banning or even
over-aggressively moderating" let us note that alt-coin discussion is explicitly subject to certain time/place restrictions by the forum/sub rules. If you break those rules, expect to be moderated. If you persist despite moderation, expect to be banned. Duh! This isn't hard, except when thou doth protest too much.
It is not honest to, by visitation and participation, implicitly agree with the existing moderation rules and their arbiters (the mods), but then act SHOCKED when playing the Censorship Card fails to win a dispute over/with them.
Does xt pretend to send transactions on the network seamlessly now or does it actually do it?
Selective censorship is where the claim is xt is an alt coin but side chains also being an alt coin are allowed to be discussed.