This is mostly good news, but would best be coupled with a promise to add security key support to iCloud for Windows. Over the long term, iCloud users shouldn't have to choose between good security, on the one hand, and keeping the cross-platform support they may already rely on and which may even justify their choice to buy a paid iCloud subscription, on the other.
Agreed. I've moved to iOS devices for my phone and tablet but am still on Windows for the foreseeable future. I might make the move to Mac with my next laptop refresh but I expect that to be at least 2 years away. I'm an iCloud subscriber but can't utilize this upgrade until then.