I'm thoroughly confused. The only effect of the employer filing bankruptcy is that a Bankruptcy Trustee may be appointed who should become the plan fiduciary for purposes of terminating it and distributing assets. In any event, absent the bankruptcy trustee assuming responsibility, the existing plan fiduciaries remain the plan fiduciaries . Interestingly enough, the OP indicates an active plan fiduciary, but also the pendency of an application under the DOL's Abandoned Plan program - and those two facts are inconsistent. In order to have a QTA appointed, one must documents efforts to contact an existing fiduciary, and only if they can't be found, or are unable to continue as fiduciary, will a QTA be appointed.
In any event, if a plan fiduciary exists, it's a fiduciary decision to approval or not requests for distributions, considering many factors but including a diminishing pool of assets/participants to pay ongoing fees. If the choose not to all distributions (a good idea, IMHO) then some "action" should be taken to effectuate plan termination and minimization of fees - else the DOL, when the denied participant complains, will question the fiduciary.
If the plan is "abandoned" under the DOL criteria, then by definition no fiduciary exists until a QTA is appointed. Where I used to work, I was the QTA, and we would have a plan to bulk distribute benefits so as to reduce fee impact. Often; however, the fees were due to us (a r/k), and we would waive those fees as to charge them might be perceived as egregious or greedy, and reputational risk outweighs revenue.
So, bottom line, who's the fiduciary NOW, and in any event allowing distributions is a fiduciary decision....