Suggestion: instead of publishing an article giving a brief synopsis of something that will be "effective immediately" and "if you don't do this by 'X' date, logins will fail", include the pertinent information for IT Professionals and Service Owners to act accordingly.
I cannot emphasize how frustrating it is for customers (and partners) to receive messaging from the PG like this - which causes an immediate knee-jerk reaction - and then have to sift through subsequent communications for pertinent details on implementation.
Measure twice, cut once - you're doing us all (including yourselves) a favor.