Do you think she handles all the calls, emails, etc.? So she probably "passes on" the information to him. What if someone from the palace told her about Philip's condition and she just didn't care? BIB does sound like something she would do since she couldn't risk Harry going back early and waking up. Plus with her assuming that Prince Philip was only in the hospital to keep her "muzzled"
even though he ended up staying in hospital for a month and passing shortly after.
Yeah, I think I read somewhere that Harry was planning on only coming back for his 100th birthday. Surely you would still visit at least once before that though.