Arvind Shyamsundar keeps track of changes:
Till such time that we have a detailed, fully updated change log, this blog post is being written as an unofficial change log for ScriptDom at least. Hopefully it will help readers understand when certain T-SQL grammar was added to ScriptDom, etc. I hope to keep it updated as we have later releases of DacFx and thereby, ScriptDom. If you have questions / feedback for me, please do leave a comment in this blog post and I will try to address it in due course of time.
Note that if there are no functionality changes for a given DacFx release, it will not feature in this table.
And again, this is an unofficial change log, so it is provided as-is and should not be in any way construed as an official Microsoft statement.
Click through for this unofficial log. As you can see, ScriptDom is still under active development with SQL Server 2022.