No, this is absolutely not obsolete! How did you come to this conclusion? Could it be that you never read these patens, Sipho?
A lot of the IP/patents were not related to GaAs, but could be used also with other 3/5 semiconductors like InP and (I guess) even ended in the OI. Nevertheless - it was the only path to survive - to skip all this and focus on a "faster" pass to products. To downplay/shut down the GaAs-project was right.
And - with this story about the 4th terminal - I have my own idea about that. Yes, could be that this terminal issue was a roadblock. But the probability is - let us say 15%, that applications in defence/space (radiation hardened tech...) could have been a reason to shift this project to "US skunkworks". Don't forget the funding of Poet/GT in the past and the cooperation with BAE. And if so, no one of the management could dare to speak about that.