The sequential version is only a requirement for AutoMerge, the bot comment explicitly says that:
Note that the guidelines are only required for the pull request to be merged automatically.
…
If you do not want to fix the AutoMerge issues, please post a comment explaining why you would like this pull request to be manually merged.
And I do exactly this - post a comment that the version is fine. There are already a couple of intermediate versions not registered in General, I cannot use earlier numbers.
That PR was just merged, probably DilumAluthge saw this discussion. The new version should be available from General now.