In this case, yes, of course—I don't really get your objection. If their own legal counsel is advising them not to let their developers use their own product over legal concerns (and what else could be the reason?) that would be a pretty good argument against anyone else using it.

Nb. I don't know whether they do or do not, in fact, let their developers use it.

Say what you want about microsoft - they've got some of the best lawyers in the world on this kind of stuff. If they're not doing it they either don't trust the tech or don't trust the law.

No but it's not a bad litmus test in this situation.