Then you realize that they don't owe you anything.

Well, in that case, you are okay with the last version of free nginx for several more years. If you use Ubuntu server for example, it ships with outdated version. A lot of companies use that (for stability and security reason).

And I predict half of the developers will protest and negotiate with Nginx Inc. to get a fork version.

Don't panic. I think it is solid enough for few years. What if half of the world is destroyed tomorrow? Well, that's a disaster.

Then you choose another open source offering or fork nginx and start implementing the features it's missing.