Last I read, RIck Perry told Trump he was not interested in leaving his post at the Energy Dept...The reality show nature of this WH cannot be called "governing" but it's unfair to Trump to expect anything more from him other than being a reality show host - The guy has no interest in the PDB, and has commented that H.R. McMaster makes these briefing sessions too long. With the attention span of a 3-year old who loves seeing people clap for him, it's not realistic to expect any more than what we're getting from Trump.
Will Zinke be next to go?...Will it be H.R. McMaster?...Will it be Shulkin? - we'll find out when Trump needs to grab the headlines to bury negative news...It sounds like 60 MINUTES plans to go ahead with their interview that will be unpleasant for Trump which, btw, would be the perfect time for Trump to grab the headlines by firing another cabinet member.