The written text will tell the story. In the whole picture, Melinda's possible verbal testimony is only one piece of the whole picture and L/E knew about it early on. I think she is walking it back a bit, probably said more than she should have.
I am speculating here; however, from what I have heard Melinda say, I interpret it to mean that Suzanne had made up her mind that she wanted a divorce and was afraid how Barry would handle this news. I think that she reached out to Melinda for advice because--as their mother mentioned--they both were married to men with similar personalities. So, Melinda had gone through a divorce with someone like Barry.
Melinda made it clear that she didn't think that Suzanne was in immediate danger. To me, that just meant that Suzanne would wait to tell Barry that she wanted the divorce. Melinda mentioned that she told Suzanne that she wanted to pray on it before she gave her advice and she also told Suzanne to take it, "one day at a time."
I think that Barry somehow discovered what Suzanne had been texting to Melinda and possibly her friend and was furious that she was talking about him behind his back. Maybe, Suzanne had even snooped and discovered that Barry was in fact cheating on her again in Colorado (as Melinda had implied was suspected in Indiana). Melinda even told Suzanne that if that were the case, moving would not solve this problem.
I think a ferocious argument may have ensued on Friday night. I'm going by what MG said, i.e., Barry looked like he had had the worst night of his life and then he left early "to make the wife happy."
Maybe, Barry gave Suzanne a chance to change her mind on Saturday. When she wouldn't, he decided to murder her. Who knows? She may have said that she also wanted to return to the Indiana home and was willing to let him have the Puma Path home.
I don't think that he would allow any of that because nobody was going to leave him or take any of the family fortune. He wanted it all.
Of course, Melinda realized pretty soon, after Suzanne went missing and was in contact with nobody, that the worst had probably happened. She then contacted police. Thankfully, they were able to retrieve the deleted text, which had to be full of damning details if Melinda felt a need to delete it lest it get into the wrong hands.
JMO.