I can only agree with everyone who's been saying it's not that hard to post an "I'm alive, taking an indefinite break" message, even as a euphemism for "I'm quitting", just to buy her time and address it later on, when she's got more time and energy to devote to it. Otherwise, it's highly, highly disrespectful of her.
It's not like people are demanding she explains in details everything that's going on. We all know her private life is none of our business, so if she's struggling with personal problems (say an illness of a loved one), we don't want her to tell us. We also all know that her business dealings outside of her channel are probably well guarded, and that, even if she wanted to, she wouldn't be able to say anything about them. That's totally fine. But you don't just ghost thousands of people (she has over a million followers on YT), people who care about you to some extent, because that's the type of brand and relationship you've built, who were the foundation for the opportunities you got, and yes, helped you make a ton of money too, taking the time to comment and interact with your content, which boosts the "algorithms", maybe watching the ads. Many people, including myself, bought her guides. I know I did it in part because I like her workout style and attitude to fitness, and in part because I trusted her (thanks to the brand/image she's built) and wanted to support her, so she could keep spreading her healthier attitude.
Her completely disappearing off her own channel and social media accounts, but being present elsewhere (a bit on the Power app thing, from what I've seen), is such a slap in the face. Actually, it would be, even if she wasn't present elsewhere.
Her followers did not necessarily directly give her money (although many bought bands and guides), but youtube and social media are just a different type of business transactions. It still is business though, and you owe respect to those who've helped you get to where you are. Of course she works hard and is intelligent, but I dare say that if she hadn't had her successful social media career, she wouldn't have been able to work on the power app, or do any of the things we've seen her do. I mean, she quit her studies knowing she was starting Youtube, didn't she? And as someone pointed out, she got to it at a time when youtube stars and careers already existed, for years, so she knew what the potential was.