The fact that Meghan appears to have been, as you said, documenting everything since she first met Harry, is actually what now to me raises suspicions about what her intentions have been all along. Especially against the background that she said as a teen, per her own Netflix documentary, that she wanted to "be rich and famous and tell her story" to the world.
Maybe it is just her Southern California, Hollywood culture and I would not go as far as saying that she had an "evil plan" from the beginning to use the Royal Family to power up her status as a celebrity, especially in North America, and monetize her fame, but I am increasingly arriving at a conclusion that she had some misguided expectations about what being a princess would be like, and, when she realized that the reality was different from what she had anticipated, she came up with a Plan B, which was the "half-in, half-out" model. When the RF didn't go along with the latter, she then got out to rebuild her life in California, which seems to have worked out very well for her, but maybe not so much for Harry.
Of course that is not the official version of how her story will be told on Netflix and elsewhere. Instead she will present it as an issue of racism, mental health, and not feeling safe in general, which are matters to be taken seriously (if true) , but which do not square well with the original "half-in, half-out" plan. I still want to hear her case further in Part 2 of the Netflix docu-series though before I reach a final verdict.
This bolded part is the biggest red flag of all to me and I imagine it was to the RF as well. That she seems to record every vaguely important moment in her life on her camera, through pictures etc will have caused alarm I imagine. Especially as she was still relatively unknown by most members of the RF.
Even trying to be charitable there is no way those video recordings they made during "Megxit" of their own phones were ever going to be just for them and their personal memories years from now.