They really have been best friends all this time. They've really made "conscious un-coupling" and conscious re-coupling" work so far. It would be nice if they actually did re-marry. It was the "Firm" and all their overbearing rules and Andrew not being around to defend her, that broke up their marriage.
After 3 of Queen Elizabeth's children ended in divorce, this is why the "Firm" has backed off on Will & Harry. It's obvious that Meghan wasn't "vetted," or her crazy family and their problems would have appeared during the vetting process.