No - there is no enforced standard for version alignment. The Python alignment was just a happy accident. You can look to Mesh Toolkit as a Autodesk authored package which doesn’t align.
Yes. In fact every update to Revit should come with an expected “automation maintenance” effort (using that term as it isn’t just Dynamo which is impacted, but all tools). You should test, fix, and re-deploy for each change to your Revit environment (including updates, patches, new versions, and add-in updates/changes). Before testing you should get the ‘updated package version’ for any and all packages (i.e. install the right Archi-Lab; install the right IronPython, etc.). This is easiest to do in a clean environment (no packages) where you just install the version needed (be sure to read the package descriptions carefully), and making sure the library gets a new package on each install. Then screenshot what you have, and close and restart Revit. Launch Dynamo again and you should have alignment on packages in the library with the screenshot. From there testing fortunately can be completely automated by way of journal automation - you just have to validate it worked and save to the deployment directory. And if they fail and take more than a few minutes to resolve, save them in a ‘update when you have time’ folder.
This is a poor policy for your IT team to review, as there is no longer a way for you to validate graphs execute cleanly in both the old and the new. Each Revit release should be made available to you as a computational designer or Dynamo user, with a budget set for maintenance and development of your automation routines. Perhaps an uphill battle, but if they can’t provide such then you should let them know that each year you’ll have to start from scratch on all the time saving automations.