Validation is a requirement to sell a product. You will note that Suresh mentioned the quad pin detectors being validated. I think they required 1800 hours of testing and they did not have one failure. I suspect that there is a failure limit before the detectors as designed receive a pass. It is essentially about tracking performance over time (aging and stress testing). So now those detectors in the Receive Optical Engine are tested again as a package to be approved for product sales. 

On the receive side they are using ALMAE TECHNOLOGIES laser/modulator so I expect they have already gone through device testing. But the same as the receive side they will be again tested as a Transmit Optical Engine once they have been adjusted to be used with the optical interposer. 

I think this is the reason they went with Almae because it provided the best fit and reduces the amount of time required to get the TROE product approved for sales. It should be noted that on the transmit side there is more heat generated and so the testing is longer to ensure that the product maintains stable performance over a longer time period re thermal management for wavelength control.