>"Once there are 1000 published articles, studied this way and that way by so many different people, we can trust that it's actually happening", but this is an ought belief.
You are misunderstanding what it means for something to be an "ought" belief. Your example is actually an "is" belief: it's a claim that across all cases where 1000s of published articles exist, most of the time the contents are true. The "ought" version of that would be, "you have moral duty to believe anything that enough literature has been published in support of," but that's absurd, nobody thinks that's a moral rule.
The Humean is-ought idea is specifically about distinguishing ethical problems of value from empirical problems of evaluation.
Your variation, that says "most of the time the contents are true", is an is statement, but it's entirely unverifiable. Good luck providing evidence for that! And even if you did, there's a very convenient out: "It's not true in this case."
The whole thing would be short-circuited by saying "When 1000 papers agree, and almost none disagree, we should take the claims to be broadly true."
Also, see how we've gone from having a discussion about the topic at hand to impossible-to-prove factual claims about how often a group of 1,000 academic papers are true? It doesn't seem like a very interesting discussion, at least to me.
You were saying that unverifiable statements were ought statements, by arguing that because you couldn't figure out how to defend a statement, it had to be an ought statement. The truth or verifiability of a statement has nothing to do with whether or not it's an is or an ought statement.
You are misunderstanding what it means for something to be an "ought" belief. Your example is actually an "is" belief: it's a claim that across all cases where 1000s of published articles exist, most of the time the contents are true. The "ought" version of that would be, "you have moral duty to believe anything that enough literature has been published in support of," but that's absurd, nobody thinks that's a moral rule.
The Humean is-ought idea is specifically about distinguishing ethical problems of value from empirical problems of evaluation.