It's all speculation at this time, until we see who the endorsement would be. What I don't get, if it's true, would be Cruz's campaign saying negative things about Palin. At this juncture, she is the ONLY Republican woman who once in a leadership role didn't back down on conservative principles.
I would assume that if Palin does support Trump, it's because there's an insiders take about Cruz's problems that they know won't go away.
I've never seen it, but the "he doesn't get along with anyone" rumors started a long time ago, before Trump even entered the race. It's possible that the arrogance needed to head a country isn't perceived well among friends and co-workers.