This doesn’t look like an EEE to me because an essential component of the second E is using new features that competitors can’t support to create interoperability pressure for end users. For example, Google pushes novel web APIs that other browsers don’t have the bandwidth to support (or that are mostly only beneficial to Google), which results in some web pages working only in Chrome, which (the important part) forces end users to use Chrome if they want web pages to work. This is different than merely competing on features that the end users directly care about—using Chrome because you think it’s faster or looks nicer. That sort of competition is much less insidious, and that’s what it seems to me that DetSys is doing here.
If DNix merely outcompetes Nix on features, that doesn’t stop a minority market segment who are unconvinced by DNix’s value proposition from continuing to get value out of Nix. If DNix changed the game so that Nix was no longer usable, then I would be just as upset as you seem to be. But I don’t see any evidence of that yet. If DetSys is EEEing, they’re still on the first E.