Is HEVC really the best option for a long term format that will still be readable in a decade or three? Something more open and standardized seems preferable.
However, that's still not answering why you think HEVC (supported by some puny little company called Apple on all of their hardware) vs any other codec. It's not like they chose Cinepak or something else as ridiculous. It's the most modern codec with the longest legs of viability.