David Hildenbrand, another very involved memory management legend is picking up the role. It will be fine.

It's not surprising to see that he wants to retire. Andrew Morton is an absolute legend and deserves it. His work will be felt for a very long time, and his transition plan is also highly professional. All the best to him.

What more do you need to know? The authoritative sources (I think lwn.net is, but I'm sure there's a ton of 'well, ackshually...' opinions) say he's unwinding his role, and that new people are picking it up. Seems pretty non-alarmist, non-brethless when you get out of the douchebag-sphere are do the basic research. But I guess you don't get clicks for "there's a change, it's being handled by adults, nothing to worry about".