Just to clarify, previously you talked about the 'latter half' of next year so I've taken that to mean AFTER the summer - but please correct me if that was not the intended meaning. If so, what do you suggest Meghan does for at least 9 months between the end of her contract and the wedding (including 4 months (or more?) before an engagement)? Moving to a different country is definitely not a full time job for 9 months - or even 4 months, if we are to assume that she spends her engagement months planning the wedding. I am sure moving and being engaged can easily be combined ?
Furthermore, I don't see how an 'earlier wedding' or even a December engagement would require a move before or during the holiday season (although it might be that she expected to move as soon as the engagement is announced, who knows?). And if they prefer a January/after the holidays engagement announcement that still goes well together with a wedding late spring or early summer
Just like you, I hope she'll take some time around Thanksgiving to visit her mother (or father in Mexico!) and probably some friends. Not sure how many friends she has left in LA, maybe some have moved on to other places as well - it seems that several of her friends live in Toronto - so she might not be as devoted to her hometown as some people suggest (although coming back as a duchess will be different I'd say); but no need to repeat that a few weeks later.
Only her mother is in LA; other than that, I am not aware of any close family relations in LA. Her father lives in Mexico; and it seems Meghan's mother is happy to visit her where she is. And let's not forget that Meghan has not been living in LA for over 6 years (but already in a different country at about 5 hours flight time), so she hasn't seen anyone living there 'on a regular basis', so that is quite different from moving away for the first time.
I am sure she will say her goodbye's in Toronto but the holidays are typically more filled with family than friends; so it might be easier to say goodbye at a different time than trying to spend time with them over the holiday season when their priority is family. That is not to say that she might not choose to spend one more Thanksgiving and/or Christmas in LA or Toronto but she could also decide otherwise for good reasons.