This is complete speculation on my part and apologies in advance if it needs to be deleted...
If BM was having an affair and SM found out about it and was planning to divorce BM; BM would be left dead broke. Given the real estate sales and other financial moves after SM’s disappearance this is quite curious.
And (major speculation ahead) what if SM wasn’t texting about her best friends’ sons wedding that ‘SM was going to be in’ but instead was texting her best friend about SM’s own wedding/marriage and that Saturday afternoon she was confiding in her best friend that Saturday evening she was going to let BM know she was planning a divorce and move back to IN. With the kids out of town, it would be an uninterrupted time to speak with him. Her friend knows the plan and right around the time SM was going to talk to BM, SM goes radio silent. Then she can’t be reached that morning.
That would certainly justify why the best friend was so alarmed by SM’s silence. Something from the best friend like “ok, let me know how he takes it” followed by complete silence would definitely me a major concern.
Sorry if that’s too ‘out there.’ The news this week really has my juices flowing.