The Boeing 737 Max 7 and Max 10 were originally due for FAA certification by the end of 2022. However, a letter sent by the Federal Aviation Administration administrator Billy Nolen to Senator Roger Wicker (R-MS) on Monday indicates that this deadline won't be met as "Boeing's current project plan timeline has the 737-10 receiving an amended type certificate no sooner than summer 2023".
If the new variants are not certified by the end of 2022, Boeing will be forced to implement EICAS, or the Engine Indicating and Crew Alerting System, into the 737-7 and 737-10. The system notifies pilots of faults on the aircraft and directs the pilots on how to resolve the issue. This system has been equipped on other aircraft families for decades, but was never implemented on the most delivered narrowbody in the world. This was part of legistlation made by congress in 2020 in wake of the two fatal 737 Max crashes caused by MCAS, or the Manuevering Characteristics Augmentation System, a few years ago. While implementing EICAS is benificial to the safety of the aircraft, it also introduces a plethroa of problems for both Boeing and pilots. The plane manufacturer would have to get a special exemption from congress if it does not wish to meet these new requirements.
Implementing EICAS into Boeing's newest narrowbodies would cost the company masses in the redesign phase and additional pilot training resources. Boeing has also stated that it would be safer to have one alerting system on all 737s, as commonality is imperative. Plenty of pilots also agree. For instance, the Southwest Airlines Pilots Association emphasizes the importance of cockpit commonality as it allows airlines to have more pilots available to serve certain routes on slightly different sized aircraft-variants depending on the demand for the route. Short haul pilots, which is the class of pilots that would be operating narrowbodies such as the 737, may fly several planes in a single day, and having the same alerting system on each of those aircrafts makes it safer and simpler for the pilots. This case is especially stronger for airlines that have only family of jetliners in their fleet, such as Southwest and Ryanair, which both only operate 737s.
Nonetheless, there are other pilot unions that would argue otherwise. The Allied Pilots Association (APA) is a labor union representing pilots from American Airlines. Having the largest fleet of any airline in the world, American Airlines undeniably has a far more diverse fleet than Southwest. This signifies that cockpit commonality is way less feasible for the airline. The APA testifies that Boeing needs to implement modern crew-alerting systems to prevent confusion during sophisticated system malfunctions. The lack of a such crew alerting system had argueably contributed to the two incidents in 2018 and 2019 involving the 737 Max and MCAS malfunctions.