Slave, I'm not questioning the need for all these things to be completed prior to getting approval. The difference, using your flight analogy, is communication. With a pending flight on a normal airline (or for most companies in my experience), if there is a delay holding the plane on the ground, the pilot will explain the reason, asking for the passengers patience and cooperation. Failure to do so will impact the airlines reputation and future business, not to overlook the possibility of passenger(s) demanding compensation for the delay or filing litigation.
In our case it seems the pilot has welcomed the passengers, thanked them for flying NWBA Air, then advised them due to ATC requirements, there would be no future communications until takeoff regardless of how long the plane may be on the ground. They may leave prior to receiving approval to taxi. EOM.
My problem isn't with the time we've been waiting for MHRA clearance. OK, maybe some. But the company has evidently decided to use MHRA requirements as an excuse to not have to say anything about anything that isn't in required FDA filings and I don't see that as acceptable.