@Vignetta I totally agree with your post, except you mention that Meghan seemed to be very passionate about the animal rescue charity.
But I can't help but remember that Meghan left one of her rescue dogs behind in Canada when she moved to the U.K. the initial story was I think that he was "too old" to travel - the dog was 5.
Then later it was claimed that he didn't like Harry and that's why he was left behind.
Finally, I think Harry claimed that that the dog became aggressive due to the trauma created from the media frenzy and "siege" on Meghan's flat.
The first option is not credible, the third seems highly unlikely - the second more plausible (and I can see the third story being Harry's way to blame everything, once again, on the media). None of them stack up to me as credible reasons for a devoted animal lover to just ditch their beloved rescue pet. Even if the dog didn't like Harry (I wonder why!), there are animal behaviourists - it's not like they were short on money or time to work on the issue.
Seems to me that she has the same attitude to pets as she does to people - she loves them as long as they're convenient for her, and moves on without compunction as soon as they don't serve her purpose anymore.