In reality, the top of the department, any department, is largely isolated from much of the day to day goings on in his/her department.

That's not an excuse. "Bill Stops Here" and all that is a must for them. They are responsible.

But, even if Wray is a white hat, info handed to agents may well get disappeared midway up the chain o' handling.

You can't have a corrupt top echelon leadership, which the Feebs and EVERY federal agency/bureau, job has, without a compliant and cooperatively corrupt middle management. And that middle management can and often does ignore the top of the chain and obeys those most closely managing them on their own day to day activities.

TL;DR

Might not matter either way about Wray.