here is a summary of the discussions. The full agenda can be found here .
We had only one topic on the agenda - a new view on interoperability testing - don't confuse it with interop which is a certification program. The program just uses the interop tests for the certification purposes. The tests that are part of interop were long ago considered as enough for testing interoperability.
However, as it's been pointed out as well as discussed many times already , the tests don't guarantee interoperability of tested clouds - they test only basic API thus they can be used for the certification program (related to OpenStack brand) at most.
Interoperability is subjective, every user may be looking for a different level of interoperability. Read the ending of the article . If there is someone who is interested in interoperability testing in OpenStack or even someone who requires that for various reasons, we could do something like this  - we could gather various tests from various testing platforms that test specific functionalities. It would provide anyone with metrics and thus allow them to compare clouds. It would be like when we're shopping, e.g. for a new computer - we have various metrics that help us decide which one suits us better like dimensions, weight, RAM, CPU, storage space etc.
From the last PTG (and several one before) it, however, doesn't look like the community is interested in running actual interoperability testing. Let us know if you disagree, we don't want to develop something that is not needed by anyone.
 https://etherpad.opendev.org/p/oct2023-ptg-interop  https://superuser.openinfra.dev/articles/new-view-on-interoperability-in-ope...  https://etherpad.opendev.org/p/bobcat-ptg-interop  https://etherpad.opendev.org/p/openstack-interop-2.0
Thank you all for attending the PTG and contributing to the discussion,