[uoaei]

Thank you! I was not. The GitHub repo has indeed been archived.[1]

Any ideas where to go for similar functionality that will be supported in the future?

[1] https://github.com/gorhill/uMatrix

[Forbo]

There seem to be several forks, although it doesn't look like there's much consolidation on merging PRs into any specific repo. Hopefully they don't just splinter off and end up fragmented and neglected. :-\

https://github.com/gorhill/uMatrix/network

[tprynn]

uBlock Origin in advanced mode is gorhill's suggested replacement. If you have never used uMatrix before most likely uBlock Origin is what you should be using, and can easily accomplish the "globally block facebook domains" either via blocklists or manually via the advanced mode.