This is not necessarily true, it is perfectly reasonable both that individual employee were simply like minded, or that given the high visibility his character they all acted quickly not to be "accused" of supporting him.
It surely looks like they conspired, and effectively it is as if they conspired to do it, but personally I believe that as a default it should not be accredited to a conspiracy (as in the dictionary meaning of hidden agreement) unless we have some direct evidence.
Especially since the possibility that individual employees were biased and like minded is much more likely and stable.
I guess I can kind of see how it is possible to believe that it was a coincidence that all companies banned him simultaneously. It's obviously overwhelmingly unlikely that it was a coincidence, but that is at least a coherent thing to believe. On the other hand, I cannot say the same for the claim that there was "no censorship".
What do you call banning people because you don't like what they have to say and want to stop them from sharing their viewpoint if not censorship?
If you want to argue that Jones should be censored, that seems like a rational and worthwhile conversation. I don't get how you can argue that he wasn't censored though.
Regarding how Facebook, Apple, Twitter, YouTube, and Spotify are different than a random phpBB forum, I think I'll just leave that one as an exercise for the reader...
"Conspiracy - an evil, unlawful, treacherous, or surreptitious plan formulated in secret by two or more persons; plot." - https://www.dictionary.com/browse/conspiracy
It also strikes me as a bit disingenuous to suggest that because he can just go create his own Twitter or his own YouTube and host things there he wasn't censored. He technically could, but that doesn't change the impact of banning him from the major services. It seems as perfectly clear that they are censoring him as it is that the big tech companies conspired to do so. Again, you may argue that it is right to censor Jones - he is either a liar or crazy, but it makes no sense to argue that he wasn't censored.
I think in isolation, it would be better if Jones didn't share his opinions. But if I had to pick between realities, and in one Jones was free to spread his conspiracy theories, and in the other big companies get to decide what we can and cannot say online? Well, it's a pretty obvious choice for me.