H&M also launched court actions whilst they were senior working Royals. They may have wanted to launch more, but they were certainly not barred entirely.
I don't think it's ever a case of a faceless official deciding what is actionable. It's the individual. They'll be advised, but they cannot be compelled to follow that advice.
It was never going to be initiated by others for them, they'd have to come up with it themselves (as they did, several times)
And in that 2-3 years, Meghan had unprecedented welcome (first unmarried partner to Sandringham for Christmas, early public engagement with only HMQ (definite seal of approval - didn't Kate wait years?)
And of course being given some pretty major patronages, which she has not had to relinquish. It is a pity that we have not seen more of her icw The National, especially
(The Countess of Wessex BTW was compelled to stop her outside work, and was in the wilderness for years)