I edited a rdl with VS2022 and the tag am:AuthoringMetadata was added to the top of the xml, is this used for anything when the report is ran or viewed. I presume (and hope) not, but haven't seen it before.
<am:AuthoringMetadata>
<am:CreatedBy>
<am:Name>SSDTRS</am:Name>
<am:Version>17.5.33516.290</am:Version>
</am:CreatedBy>
<am:UpdatedBy>
<am:Name>SSDTRS</am:Name>
<am:Version>17.5.33516.290</am:Version>
</am:UpdatedBy>
<am:LastModifiedTimestamp>2023-03-31T15:36:51.5318671Z</am:LastModifiedTimestamp>
</am:AuthoringMetadata>
This started appearing for us in the recent versions of Microsoft Reporting Services Projects Visual Studio extension (between 3.0.6 and 3.0.7)
Given its so recently added, and we have a mix of reports with and without it. I would say it has had no bearing on anything currently.
As an aside, it is very frustrating from a source control point of view. As it will guarantee a needless merge conflict if two people make separate edits anywhere in the report.
*** Update 2023-05-25 ***
On the extension's Q&A page Microsoft have replied confirming its for future features.
The authoring metadata was added for report creation and editing because we now have more tools that can author RDL then we did years ago. We use the information to fuel future investment.