First of all I agree with you about Bart's job, this totally slipped my mind. I think this was discussed before. Yes, he might have asked her to stop posting but yet again - why can't she post about a designer bag once a week? Who would it hurt? Her channel is not political or controversial. Or at least make an announcement that she is leaving for good. If she said it was because of her husband's job that would be a legit reason and everyone would be fine with it.
In my personal experience and just thinking of other YouTubers who did that - people do tend to take long breaks when they are dealing with personal stuff such as divorce, money problems, health issues, infertility etc. They do it offline as well. Whenever I have some problems I tend to shut down as well. I am not sure about a divorce but I certainly think there are bigger issues there. Not sure about wishful thinking. Most people who comment on her instagram page are her fans. I just think this is one of the most reasonable explanations.
As for Kat, wow I would be PISSED if I was going through something and my friend said that to hundreds of thousands of people. So either she was ok with that or Kat just wanted to stir the pot. In the world of social media you don't just say something like this for no reason.