Or it could be simply a convenient excuse. The strain of a funeral is bad enough for many, let alone a pregnant woman. And although I understand the sidestepping around the Oprah interview right now, let's not pretend that it didn't happen. I imagine that after Meghan's accusations and the "unproductive" conversations that followed, neither party might be eager to see the other right now.
Let's hope there's nothing wrong with Meghan's pregnancy and she's just being cautious. For all the good wishes of "mending the rift", "healing the wounds", etc., I don't believe it's going to happen and I believe that a reunion so soon, for such a grave occasion and under the sharp eyes of cameras is bound to be tense. A good deal of the coverage won't be on the funeral but on any tiny hint displayed of mending the relationship or worsening it anyway. With Meghan there, it would have been a thousand time worse. My guess is that everyone understands it and the doctors' advise might be actually nonexistent.