That's a bit too strong a statement to make based on a two-year-old still-open PR with an uncertain future. It seems like it might be coming at some point in the future.
They recently got a fair bit of interest on the mailing list https://goo.gl/kvNwC1 and raised some money for it as well https://github.com/NixOS/nixpkgs/pull/9250#issuecomment-3208....
I'm pretty sure I read somewhere that it's planned to go in the next release.