Could it not be the case that the internal testing was conducted by the european partner and not POET? To me it seems they have received their samples and done their own testing and fedback to POET their requirements for Beta samples.  Only minor tweaks are needed, as such they have sent Beta samples off for production. 

The paragraph below is referring to the samples that have been received already and therefore tested internally thereafter by our parteners.

The sample delivered to a leading European optical systems company supports a combined transmit and receive Optical Engine product, which has been developed for an innovative 400G transceiver application.  The Alpha samples demonstrate excellent margin to the transmit link budget at operating temperatures with excellent optical eye margins (an optical eye is a fundamental measure of data signal integrity). Internal testing shows that only minor improvements are required for a Beta release that would meet all of the requirements for production. These changes have already been incorporated in the Beta designs, which have just been released to the mask shop for production.