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.
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.
i assume they and other devs in the space also are working with apple to get the necessary API calls for feature parity with prior versions.