That's not necessarily true. The article mentions this. While ObDev still doesn't have all the APIs necessary to implement all the features of Little Snitch using NetworkExtensions, they are working on it with Apple and feature-parity is not expected to be an issue for the 10.16 release.
Are they a big enough developer to really influence Apples API design? I’d think companies like VMWare etc. are more likely to be able to push and prod Apple to do something than a little guy like the Little Snitch dev.
I don't think they'd say "we're working with Apple" if that wasn't the case.
Also, I wouldn't be surprised if people working on the Network Extension framework were exactly the kind of people who want to be able to continue use Little Snitch themselves.
My guess: There are people inside apple that rely on and value LittleSnitch and they have enough influence to work with the development team and ensure APIs are built to align with Apple's Security/Privacy goals while still allowing LittleSnitch to function as it currently does.
Little Snitch might be the penultimate use case for Apple. If they’re using all the features and are a small highly competent team, they’re probably much easier to work with and can iterate much faster than a huge company the size of VMWare etc.
Little Snitch is wildly successful, and there are many people in security, myself included, who can not and will not use a macOS daily driver without it being available.
It’s good but not as good as LS in network management. However, HO does allow for read/write management, which is a significant advantage over LS, which does now have that capability.