This is not evidence, and it is unlikely evidence would be released. The Administration (as is usually the case for any US executive on any issue unless they are seeking action that requires legislation or a court verdict or something similar by some formal body outside of the executive branch) is not engaging in an effort to prove anything to anyone.
This is an analysis report with information (including most significantly the IOCs in the accompanying files), some of which is previously released and some of which is newly declassified, for use in defending against and forensically identifying attacks by the threat groups identified.
No one is passing this off as evidence of anything.