AdoptOpenJDK offers two builds builds for each version, HotSpot and OpenJ9. Adoptium doesn't. Instead, there's only one downloadn, which makes reference to "Temurin", whatever that is. A quick google search lands me on an Eclipse project page which describes Temurin as follows:

"The Eclipse Temurin™ project provides code and processes that support the building of runtime binaries and associated technologies that are high performance, enterprise-caliber, cross-platform, open-source licensed, and Java SE TCK-tested for general use across the Java ecosystem."

I don't know if I'm reading this right, but it seems that the Adoptium packages (were AdoptOpenJDK) are slated for Sept. 30 the latest: https://github.com/adoptium/adoptium/issues/73