It's a third party thing that isn't maintained by the SFML Team, as such it wasn't explicitly mentioned. NuGet is used by a lot of libraries, so there's really no reason to think that it wouldn't work in one or the other way.
As of how long it will be maintained, you'll have to ask the person who maintains it.
Maybe at one point I'll get around to take a look at it and possibly add a note somewhere in the tutorial.
I moved the topic to the Help section of the forum since it was a question for help after all.