That's pretty much the story that's being reported - Trump wanted a change before beginning negoiations with North Korea. Remember that Tillerson undercut Trump last fall when Trump went hard on little Rocket Man and Tillerson was saying their needed to be talks with them. Trump's position has brought the NK dictator to the table but with the US in charge.
I think that was kinda the opposite - those were the public appearances ... no wonder Tillerson got sick in Kenya ;)
Isn't Trump going to do exactly what Tillerson said, start talks?