A famous criticism of Falsificationism was that it was not falsifiable itself.
So I guess we shouldn’t bother making sure knowledge is falsifiable and go back to simply claiming stuff that can’t be tested?
So the question is if things are only going to turn out one way, that we’re all going to believe what’s true and what’s not true, regardless of whether it actually is true - yet this goes for all stances, even Free Will. Even if Free Will could be true, and you decided every choice free from causal influence, whilst somehow also being influenced by your experiences/preferences/tendencies, and also able to influence causal events even though they don’t influence you, except in the ways they do (you get the picture), things would equally only ever turn out one way, and we’d all believe what’s true and what’s not true, regardless of whether it actually is true.
What’s the difference to the argument, whether Determinism can model exactly how the self is entirely influenced by causation, or if Will tries to claim that you’re both partly influenced whilst also not influenced at the same time?
I think the intention of the question is to frame “testing falsifiable truth claims” as only possible if you could have done otherwise, yes? If so, putting the answer of Free Will into the question itself commits the logical fallacy of “Begging the Question”. What’s really going on is that the consequences of testing amount to determining that you recognise truth from falsehood to your determined ability. The danger here to is to confuse Determinism with Fatalism, and to think that you’re destined to think and act the way we do regardless of what tests we do - this is not the case. The difference is that with Determinism you are determined to react to testing in the way you are determined to, and this causal chain can potentially be followed to work out the way someone thinks and acts in advance, where Fatalism claims in advance that one will think and act in a certain way regardless of any causal chain. Both can result in foresight, but the means to those ends are the difference: one depends on interactions, for the other your interactions are irrelevant - and it always tends to be the latter that Free Will advocates are actually protesting against, which they confuse as Determinism when it is actually Fatalism that they don’t like. I think the question probably wants to put Determinism in terms of Fatalism, like it doesn’t matter what you do, but in Determinism it does matter what you do. What gives this away is phrasing like “we are all just determined”, as if the core of Determinism itself (i.e. determining) was irrelevant.
What ends up happening is that those who are determined to want to test claims, and those who are determined to recognise truth from falsehood will succeed and outbreed those who fail in either or both of these respects. If you are determined to think and act the way you do, the ones that believe what is closest to “whether it is true” will proliferate, and the ones that believe what is less close to “whether it is true” will die out - that’s the real test. Natural Selection is a neat answer to the question, which is why there are a lot more determinists around today than there was even just a few millenia ago. It started with people reacting to situations largely instinctually, one case at a time. It evolved to the personification of consistent events in the form of multiple gods, who determined each type of case as the prima causa in their own field. It evolved to the consolidation of these forces into one God who was the prima causa for absolutely everything all at once at all times, except able to give you your own limited ability to be a prima causa and therefore solely responsible for your own decisions, to be tested and judged by God Himself - the birth of guilt. These days, Free Will advocates still hold on to the idea that they are their own prima causa who can choose ex nihilo like “God Himself”, often after the death of God in their everyday lives with more and more Secularism around the globe. Intellectuals have learned to quantify and harness the forces formerly attributed simply “to God”, allowing Compatibilists to simultaneously think of themselves as a prima causa as well as being able to harness Determinism - the best of both worlds. But really they are only yielding the creations of the Determinists who understand how causation works through everything, even “the self” - this is the next evolution. “Historical Materialism” in action before our very eyes (though I would correct “Materialism” to “Experientialism”) - that’s how you step back and analyse Determinism’s feedback upon itself.
So yeah, still 100% Determinism (only tentatively maybe less than 100% Determinism if and only if there is any indeterminacy at play underneath anything - order emerging from literal chaos, not just from complexity) - until we evolve not only out of Free Will altogether, with everyone not only up to the next step of hard Determinism, but also beyond to the next step after even that - assuming this is possible. But for now, yes, 100% Determinism.