Again, this has been repeatedly debunked and disproven by multiple disparate sources. Including an attorney who writes at the Federalist completed disputing his own outlet's work.
But since you insist, I'll provide direct evidence that shows Sean Davis is intentionally misleading people because he knows none of his audience will actually go and look at both documents.
Here are two screenshots. One from the current revision and one from the version that immediately preceded the current version.

Top version is the current version that Sean Davis claims "was changed to allow secondhand information." The other version is the EXACT SAME version that Sean Davis made his screenshot from. But, instead of making a screenshot of the exact same question and area as any logical or sensible person would do, he instead made a screenshot of a completely different part of the document. He even chose a part that isn't actually part of the whistleblower form itself, and that instead is a discussion of the ICIG's guidelines for determining whether or not a concern is credible. In doing so, Davis completely omitted that the ICIG stated in his original letter to the DNI that he already possesses direct corroborating evidence that proves the whistleblower complaint is credible.
As you can see, both forms allow for a whistleblower to include secondhand information that they were given by other parties. But, somehow, Sean Davis didn't make a screenshot of that. Even though it is an apples to apples comparison of the virtually identical question of: "I know about the information I am disclosing here [because]..." Instead, he skipped that part of the very document he claims proves his case, and instead provides a tight and context-less screenshot of an entirely unrelated part of the document.
You can continue to claim that the document was changed to "allow secondhand info" but you're simply repeating an outright lie. Both forms ask virtually the exact same question, and both provide an option for someone to make a complaint based solely off of supposed "secondhand" knowledge.
The section that Sean Davis misleadingly quoted is a discussion of what the ICIG requires to forward the complaint on to the DNI. And, as I explained above, the ICIG stated in his letter to the DNI that he had obtained firsthand corroborating evidence, and because of that he deemed the complaint credible and forwarded it to the DNI.
If this is Trump's entire defense then he's screwed.
I await your retraction, Matt. I'm sure that you'll do so considering I provided direct and irrefutable evidence from the very documents in question. You were mislead because you wanted to believe something was true. How do you think the Federalist gets clicks and gets those sweet ad dollars???