They are not "decompression warnings". The decompression warning is a red "CABIN ALTITUDE" light that is accompanied by an audible horn. That occurs when the cabin altitude exceeds 10,000'.

The annunciator is a yellow "AUTO FAIL" light that is located on the pressurization control panel. It will be associated with both yellow MASTER CAUTION lights and "AIR COND" on the right Recall Panel on the glareshield It means that the active auto pressurization controller has failed. If the green "ALTN" light is also illuminated, then second, identical, auto pressurization controller has taken over. If the "ALTN" is not illuminated, both controllers have failed and you switch to manual mode to control cabin pressurization.

For the exit plug to have caused the "AUTO FAIL" light, it would have had to have been a large air leak, too large to be compensated for by the outflow valve. In such a case, there would have been significant noise in the area of the door which would be noticable by the passengers and flight attendants. In such a case, the second controller would also be unable to control pressurization and would be assumed to have also failed. I have not seen any mention of that in the reports. They've all said that the "AUTO FAIL" light illuminated and the crew, following the NON-NORMAL checklist, selected ALTN.

From what we know so far, it doesn't appear that there is a connection between the two events. Will have to wait for more information to know for sure.

As far as the groundings, I have not heard that the FAA has issued a return to flight procedure. For now, the inspections proceed and the data is sent to the FAA to be analyzed. When enough information is gathered, a return to flight procedure will be issued.

I have also heard that Alaska sends their new deliveries to a contractor in OKC to have the internet system installed. This installation may involved removing and reinstalling the exit plug. That has not been confirmed by any official sources.

We should know more soon.