Earlier quoted context omitted.
Technically the DMCA does not match the format and/or include all required information. From what I've understood a DMCA MUST include a list of the works being violated. The RIAA also failed to conform to GitHub's standard format, although using a standard form if available is perhaps something you SHOULD rather than MUST do..
From a substantive perspective, you're thinking of a different area of the DMCA, for noticed related to copyrighted works. The RIAA notice at issue here was based on 1201, for tools used to circumvent copyright, and so it's not necessary to disclose the works being violated. From a formatting perspective, format is generally irrelevant to notices like this because the law does not state a particular format must be us…
And while formatting is somewhat irrelevant from a legal standpoint it is still one of the tools Github uses to ensure that their take-down requests contain all the required information. Acting upon a request that doesn't conform to the format is risky.