Probably noticed not many people upgraded as they would have assumed they would.
I bet the next time it “appears” they have added something that makes the update irresistible.
As it stands, with the “pulled” update, there was nothing on offer except the crippling of your drone.
You old cynic, you…
Who wouldn’t want to upgrade when the release notes contain such amazingly tempting new features such as “Optimized flight safety”!
Which as you suggest Steve, actually translates to, “the bugs which allowed people full freedom of their own drone are now fixed” 
Or not of they have pulled it…….
Looks like it is back
Don’t know not checked and won’t be
It was - but then it has gone again today!
Two weeks later…
It never came back.
Weird, eh?
My guess would be a rushed/botched update (re DH certificates).
My fear would be they’re now using this time to put a more permanent fix in place 
I updated my Mavic Air2 today and it updated to v01.01.0610 says this is the latest.
Date: 2021.10.14
Aircraft Firmware: v01.01.0670
Remote Controller: v04.11.0016
What’s new?
Notes:
DJI full of useful information as always I see… 
New Air 2 and Air 2S firmware en route. Details to follow.
DH users - do NOT update!!
Date: 2021.11.18
Aircraft Firmware: v01.01.06.90
Remote Controller: v04.11.0016
What’s new?
Notes:
What did you do today, I released a firmware that fixed some bugs 
Those would be the bugs introduced by the last update I presume.
The bugs that I introduced last time I wrote a firmware update 
They’ve fixed the bugs (holes) that DH used for its exploits 
Classic - ask them to fix a problem that affects most users and sod all happens - instead they spend their limited resource time on making life more difficult 
