This is one of those situations where regardless of what the truth is for a specific incident, the pressure generated by the perceived reality must be a good thing by forcing action where it clearly was not urgently felt enough. It's entirely possible the latest ET incident wasn't related to MCAS, but there's absolutely 0% chance that the concerns about MCAS are immaterial to safety at this point, so what better time to use public opinion to pressure Boeing and the US regulatory agencies to address this?
Sure, the counterargument is along the lines of "How do you know it wasn't urgently felt enough? You shouldn't rush something like this, Boeing needs time to..." to which the response is, you're telling me before being rushed they were deliberately continuing to put planes in the air that were and are unsafe, know about it and that wasn't cause for shutting things down and/or creating urgency?
Not an argument anyone with any logic education under their belt wants to be on the side of.
Point being, engineering reality aside, political reality is in a perfect spot to force action. This is, undoubtedly, positive pressure, even if it isn't pleasant in the short term. One would think flight crew, cabin crew, ground crew, passengers, beancounters and everyone else could agree on at least the importance of the urgency of addressing whatever the concern is with systems, regardless of why it's being addressed.