Bitcoin core has made the most important contributions to Bitcoin, and you have no fiduciary to "the Bitcoin network". And thanks big ups!
But if you, or some other core dev(s), did have a fiduciary duty, financial incentive, contractual or verbal agreement with someone or some organization to make specific changes to code do you think it would be appropriate to disclose that?
Probably not right would be my answer. Because there is no way of enforcing that outside the courts and Bitcoin devs have no contractual obligations to Bitcoin network so all disclosure would be legally voluntary. Plus if some devs disclosed all their funding it does not mean less scrupulous devs would do the same so that would make a situation where ethical minded devs report their funding and non ethical ones do not which is not good.
Ps thx for posting this on nostr.