Probably the key to eventual clarity is at PJRC's forum. PJRC makes Teensy. Imho it's a great product, and the owner, Paul Stoffregen, a great engineer and person from my experience using their products.

https://forum.pjrc.com/index.php?threads/open-source-teensy-...

My summary:

1. SparkFun and Adafruit are in conflict 2. SparkFun manufactures Teensy under license from PJRC 3. SparkFun cuts off Adafruit as a reseller 4. Adafruit can no longer sell Teensy 5. Adafruit posts on PJRC forum announcing an open-source Teensy competitor 6. Paul posts that it's outrageous in terms of etiquette that they're announcing a competitor on his forum. Adafruit's own forum only allows discussion of Adafruit products.

He's allowing it despite mixed feelings.