I don't think you really believe, were the shoe on the other foot and you were the one organizing Strange Loop, that there's nobody you'd consider excluding.
But I would (and have) based on their political actions.
Regardless of how you feel about Yarvin's politics, he's not trying to force them on you. He's not trying to change the way you run your business or conference. On the contrary.
I can't say the same for his opponents however, who as well meaning as they are are too dogmatically driven to notice how nuanced this issue really is. If people like this join a group, they will either try to modify its politics and excise the members who don't fit the new order, or destroy it completely, driven by a belief that they have the moral high ground. And since they primarily work in the realms of words, their primary tactics tend to be in changing and obliterating the meanings of words to control what is being said. They'll alternatively go from claiming that words have no inherent meaning to attempting to redefine existing terms to mean different things to change what other people were trying to say.
The reason Yarvin concerns them is because on some level they believe he shares these same motivations and intents. I have no idea if he does, but I sure hope he doesn't.
In that Carlyle essay, he says these, among other things:
"Once we get this far, we are almost all the way to Carlyle on slavery. We have not agreed that a man can be born a slave, but we agree that he can sell himself into slavery. That is: he can sign a contract with a master in which the slave agrees unconditionally to obey and work for the master, and the master agrees unconditionally to protect and support the slave.
Moreover, this contract need not be a mere expression of sentiment. It can and should be enforced by the State, just as a loan is. If the slave changes his mind and runs away, the State will capture and return him, billing the master for the expense. Or at least, these are reasonable terms under which two parties might agree on the permanent relationship of master and slave."
"A person makes a good slave if he is loyal, patient, and not exceptionally bright or stubborn. But even great intelligence is not necessarily a bar to a good experience in slavery, as the experience of many Greek slave philosophers, such as Epictetus, shows. A slave must carry the unique burden of personal dependency and obedience, which we are all used to expressing only toward impersonal government agencies."
"Of course, like gay marriage (or ordinary marriage), slavery is not without its abuses. When we think of the word 'slavery,' we think of these abuses. Thus, by defining the word as intrinsically abusive, like marriages in which one party beats the other, we can conveniently define away all the instances of slavery (or, for that matter, marriage) in which the relationship is functional."
I mean, if those are not actually supporting slavery, it seems to be only because he takes care to voice a lot of pro-slavery rhetoric without actually crossing that line.
Moldbug did in other places explicitly denounce hereditary, chattel slavery and called it evil.
His actual view seems to be that it should be legal for a person to sign a permanent, life-long employment contract, mediated and regulated for abuse by the state, where the person gets a guaranteed wage in return for having to provide labor. The idea is that for the lower end of the bell curve, this is a lot more humane than subjecting someone to the capriciousness of the capitalist system, where a person can be fired at will. Note that some on the left have made the same argument. There was a leftist critique of the end of serfdom in Eastern Europe, by which they accused the end of serfdom of being a greedy power-play by the feudal lords, who wished to renege on their obligations to provide for the serfs. Does this view make Moldbug evil?