The latest view from Boeing, 14 June,
https://aviationweek.com/paris-airsh...9913b830825021
“I can’t give you a specific timeline.“
The other comment (suggestion) of a
phased implementation (mods / certification / return to flight ?) might add to FAAs difficulties in achieving certification consensus, without which their credibility remains low.
Alternatively, Boeing would have to justify prioritising modification action to certain operators over others, although this would be eased by separate certifications.
Neither Boeing or FAA might be able to achieve the ideal solution, but what would the compromise be; money - politics vs sacrificing regulatory management.