This thread is just another line of thought solved by Experientialism.
A quick recap of the fundaments in case you're still not acquainted:
Experientialism distinguishes between Continuous Experience and discrete experiences - the former being "the Truth", which is that experience has no gaps of nothingness to separate things, and if there are gaps of somethingness to separate things, there are no gaps of nothingness to separate these gaps of somethingness from the things they separate etc.
As such, experience is fundamentally continuous.
However, to speak of experience in any useful way, one needs to abitrarily dissect it into discrete experiences according to what is deemed a useful way. This is the only way to achieve knowledge, however wisdom reminds us that knowledge is necessarily removed from the truth by virtue of it necessarily being in terms of discrete experiences instead of Continuous Experience. Thus utility is not truth, though "truth" is commonly used in lieu of utility in the "relative transitive" sense: that something is true to experience to a certain relative extent - as opposed to ever "being True" in an absolute intransitive (i.e. "True" not "true to") sense.
So as we can see, there is a fundamental explanation behind the first and last lines of the opening post:
"Free will is interesting only in that it informs our thinking about moral agency. It is metaphysics, and therefore not to be taken seriously. It's a useful assumption, but it is not a primary consideration in social justice."
and
"What in god's name does "universal truth" even
mean?"
To address some other lines in the opening post (placed within inverted commas):
1) "Universal truth" is just Continuous Experience that doesn't
mean anything, it just exists. It only means something when it is broken down into discrete experiences that acquire meaning insofar as they are reconnected with one another to approximate the
absolute Truth of Continuous Experience to some relative degree. Meaning is a
useful means back to the
Truth.
2) "A claim is true or false" applies to discrete experience and how well we've broken down Continuous Experience into concepts that can be associated with one another in a way that's
more or
less true to their continuous origin.
3) "Epistemology is all about God" is just a less well defined way of saying you can only create knowledge via dissecting discrete experiences from Continuous Experience, which are more or less true
about Continuous Experience. Continuous Experience is no
God though, it's just how the concrete form of existence (in the abstract) presents itself as itself.
4) So with discrete experiences by definition being relative, the opening post's statement of "There are no necessary truths" is explained.
Experientialism makes philosophy's formerly "peculiar study of language" much clearer, right down to its logical fundaments - as tabbed out just above.
There's a later glib comment about the seemingly paradoxical "The truth is that there is no truth".
Experientialism solves this as well:
By differentiating Truth from utility, the seeming paradox resolves to something like "There is utility but it is not truth".
The corrected version retains the meaning of "no truth" in the seemingly paradoxical version, yet it eliminates its apparent internal contradiction by more accurately putting the statement in terms of utility instead of truth.