Thank you for your comments and answers.
Yes, I understood that oracle would commit to latest openjdk, and as
said by mark reinhold in "who is in charge" talk, that they 'want java
to be around in 2030' :)
but as you said too, they will not commit to any maintenance branch, and
that is the point: backports and LTS.
I maintain legacy software and could not update my application every 6
months with a new major java version : ok for my code, but I don't know
about glassfish?, spring? other libraries I use like mongo client, sql
jdbc driver? then update old production servers hell ... no way
with the same major java version it is ok once a year if necessary for
patches of course. Nothing exceptional.
After digging a bit, I found a medium post with mention of a twitter
message talking specifically about LTS release provisioning by
adoptjdk (the link you gave).
https://medium.com/codefx-weekly/no-free-java-lts-version-b850192745fb
I did not see it first time but in the adoptopenjdk/support/roadmap
section there is a clear mention of LTS release supported for 4 years.
https://adoptopenjdk.net/support.html
The bug fixes backport is not very detailed but there is a clear message
of intention. Let's see how it works.
As you said this is where maintainers have to step in.
This adoptopenjdk initiative is really nice.
bests,
Alain