Honestly I don't agree because the way mag and Jack grew on each other is incomparable to ending up w a random person. If Jack weren't involved, mag wouldn't have been reborn. Just like Jack's mother said it's fated to be.
I respect your choise, honestly I do not belive fate nor in gods.
Neither do I but I don't think our beliefs are relevant in this story. And I'm saying that a 3rd person wouldn't belong in the plot.
I actually dont think fate was the end message here-- I think the message actually was ultimately "fate is what you choose". Jacks mom for example knew her "fate," but still decided to "choose" what she wanted to do in the end.
I would prefer if Mag end up with a 3rd person who have nothing to doo with the past and her death.