The loopholes in this "commitment," e.g. allowing Apple to determine unilaterally whether, say, Servo has a well-enough-monitored software supply chain before giving it access to JIT capabilities, give Apple an iron fist over the ability to use this engine in practice in the EU.
But there's also a world where Servo, with funding like this, can achieve these requirements and Apple (begrudgingly) follows the intent of this policy to avoid further regulatory action. And suddenly there's a new browser on the block that can push the boundaries of mobile web capabilities in ways that make the web better overall, and push standards forward as well so that maybe, just maybe, non-EU folks get the benefit of these innovations down the road. One can dream :)