The FAA must meet the standards for the other regulators expectations of them
This is a very important theme. The world's other regulators work for their citizens. The citizens, both as passengers, and as taxpayers, employ the regulators to be the knowledgeable and objective intermediaries to assure the safety of the flying public. The regulators develop and then apply internationally accepted design and manufacturing standards. And, commonly, they accept each other's work via bilateral certification agreements. Not so much this time. The FAA has broken faith with the other regulators, and they are questioning the completeness of the FAA's certification process. The bilateral agreements allow any authority to independently "familiarize" themselves with the certification of another authority - for the re introduction of the MAX, they're doing it!
The citizens have every right to assert their demand for design compliant planes for their safe travel. They can do this by asking what type they're being booked on, and by demanding the independent evaluation of their national authority. Some national authorities, including the FAA, employ a system of delegation of certification activities to specified persons in the manufacturer's company. If the system works properly, the public's interests are well represented. If the manufacturer has too much influence over their delegated staff, there could be a problem. In the case of the MAX, there was a problem. The FAA would rather not admit it, but the other authorities see what's going on, and are going to check for themselves.
The FAA's and Boeing's desire for a schedule for this will be missed. Worse, would be the FAA tries to recertify the MAX before the other authorities do, that would look bad! And, worse when they realize that though that might enable the MAX to fly US domestic, it would not be accepted internationally,
That would be embarrassing!
The FAA's miss on past certification activities on the MAX have been exposed to the world, and they have no choice but to be thorough and transparent in the recertification effort, and they and Boeing take their lumps in the process.