Tech doesn’t exist in a vacuum. When team W is tasked with X, and has the possibility to use tech Y, which they are seriously acquainted with, and tech Z, which

Tech doesn’t exist in a vacuum. When team W is tasked with X, and has the possibility to use tech Y, which they are seriously acquainted with, and tech Z, which they barely touched, it makes perfect sense to go with tech Y as it’s much more efficient to get to speed and evaluate risks. In fact, as long as risks are evaluated and cleared regarding Y, there is no reason not to go with Y. As for actual risks, remember, this is MS, not some random shop: at any point if they’re dissatisfied with Chromium in any way, they have enough firepower to fork Blink, just like Google forked WebKit from Apple, and like Apple forked WebKit from KHTML, and do whatever they want.