@NCperson
You are correct. When reading the actual notice 2023-11 rather than the press release, it explains that a postponement (under a certain section of the tax code) is not an extension (as defined under a different section of the code). So the official deadline was always April 15 and was not extended in a way that would extend the amending deadline. (They then go on to grant discretionary relief to give people a full 3 years, but that is different than recognizing July 15 as a new extended deadline because it wasn't an extension.)
