I haven’t watched that video but in my opinion Markle has shown no indication of EUPD (BPD).This is gross and massively stigmatising to people who have bpd (several people on this forum from what I remember). Plus all this 'beta' men crap...
People struggling with that are so terrified of abandonment and rejection that their emotions are truly all over the place, to the degree that sustaining relationships and jobs are close to impossible. They also tend to be concilliatory and forgiveness-seeking when in crisis because their worst fears (of being abandoned) look like they are being realised.
Markle had a 10 year relationship with Trevor, a two year relationship with Cory and held down a job for 6 years on Suits. She is not emotionally unstable. Quite the opposite.
She - to my mind - is the most obvious example of Narcissistic Personality Disorder I have ever seen played out in public (in sheer pathology she’s worse that Trump even though the effects of him were greater as he gained real power). I think she was already there when she met Harry but it’s tipped over into malignancy - where she’s actually looking to cause harm - since she joined the BRF. This anger and lashing out is THE classic response to narcissistic injury.
Far from being emotionally unstable I don’t think she actually has any recognisable emotions at all, except anger. This makes her sociopathic. This may sound hyperbolic but it simply means you lack normal empathy and emotion which I think more than applies to her.
An interesting question is what the fuck happened in her childhood that fractured her to such a degree? Sure she was spoiled but her self-esteem and sense of worth is in the toilet (which is the cause of NPD) & it takes more than indulgent parenting to cause that.