Just being nosy 
, what exactly is the "Let’s Encrypt Policy Management Authority" and how is it different than "Let's Encrypt" (or ISRG, I guess)? The CP/CPS says that the PMA is what approves the document and handles revisions. Is it just a committee of people within ISRG, or is it someone external?
While I'm definitely curious about that too (and about ARI adoption in general), I'm also curious about how many were renewed at all. Last I checked, certbot checked OCSP and not ARI, so it would be renewing within a day of it being revoked if run on the recommended schedule. (And of course, roughly a third had probably already been replaced hopefully just based on scheduled expiration anyway.)
And was there an email sent to affected subscribers too?