Here's a bit more info. Choosing the appropriate license is tricky. Since we cannot open source and support/distribute VST2, VST3 requires GPL3. And Martin doesn't want to lose the MIDI output features of VST2 (for talking to the actual hardware JX8P and editing it etc.), which VST3 has royally screwed up.
Another possibility is simply to wait out and see how CLAP format pans out, since that will realistically allow open sourcing under a non-GPL license yet still be able to provide VST2, VST3, AU etc. through various wrappers.