I believe the "hoarding the fix" comment was in reference to the patches for Server 2003, XP, and Windows 8 that were released publicly for the first time over the weekend (but had been distributed previously to customers paying for custom support) [0].
source: https://arstechnica.co.uk/security/2017/05/wcry-microsoft-is...
So I don't really know what you mean by 'hoarding the fix'. The patch was not initially released to some OS versions because they are NO LONGER supported.