Is there a summary of the state of play?
It will depend on your country, of course. Here in the UK there seems to be a shortage of everything, not just tech. I was lucky enough to get the base Max Studio on 18 Mar, but would really like more RAM, and SSD, if not an Ultra rather than Max, but the lead time seems to be 3-4 months, presumably because of a memory shortage and Chinese lockdowns.
In the U.S., base Maxes are readily available from Apple stores and other resellers, but base Ultras are currently at a trickle.
Recent posts on Studios built to order suggest that a fair number of people are starting to get both Maxes and Ultras 4 to 6 weeks before the beginning of their original delivery window. This is not confined to the U.S. The day before yesterday, a person in Switzerland reported receiving his computer 7½ weeks before the start of his delivery window.
It's unclear what impact lockdown measures in Shanghai are having, but it seems clear that there's a backlog of freight at Hong Kong airport. People report that their computer was stuck at the airport for 3-5 days, but moved rapidly after it left Hong Kong. I don't see any demonstrable connection between the availability of particular components, such as memory, and delivery. There appear to be very few late deliveries, and a spate that happened 10-14 days ago seems to have been caused by courier tracking problems.
The delivery window for the Max in my signature, ordered in New York on April 1st, is June 27-July 11. Given posts over the last week or so, I think that there's a real possibility that I'll receive it sometime between the middle and end of May. I think that the wildcard is coronavirus measures in China.