Boeing said all that?
The first part is a quick resume of the Boeing/FAA EAD 2018-23-51. Read it.
* About urgent and safety:
"Due to the need to correct an urgent safety of flight situation, good cause exists to make this AD effective in less than 30 days."
* About unsafe condition:
"This AD was prompted by analysis performed by the manufacturer showing that if an
erroneously high single angle of attack (AOA) sensor input is received by the flight control system,
there is a potential for repeated nose-down trim commands of the horizontal stabilizer. We are issuing
this AD to address this potential resulting nose-down trim, which could cause the flight crew to have
difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss,
and possible impact with terrain.
* About MCAS:
"The 737-8/-9 uses a Flight Control Computer command of pitch
trim to improve longitudinal handling characteristics. In the event of
erroneous Angle of Attack (AOA) input, the pitch trim system can trim
the stabilizer nose down in increments lasting up to 10 seconds."
* About AFM Revision of the Operating Procedures:
"Within 3 days after receipt of this AD, revise the Operating Procedures chapter of the
applicable AFM to include the information in figure 2 to paragraph (h) of this AD."
You can debate the details of my quick resume wording, but be assured that I have no intention to voluntary distort the EAD importance.