There’s a simpler explanation. Trump needs to build public support for the firing of Sessions before he can pull the trigger.
If Sessions was smart he would resign right now with honor. If he doesn’t resign, he’ll get roasted for a long time and will get fired when he has no support left and people are just begging Trump to let him go.
I think President Trump really started to lose patience with Sessions when Mueller began to look into his personal business affairs.
He probably thought that Sessions should have had his back and fired Mueller over this and the conflicts of interest.
I believe that there is a real rift between Trump and Sessions and that Trump is feeling out his base to see how it would go over if he fired him.
Donald Trump prizes loyalty highly and I think that he feels that Jeff Sessions wasn’t loyal to him when he needed him to be.
No doubt Trump is not happy with Sessions recusal. But I believe all the recent fire from Trump is about getting him to buck up and be more assertive. I’m sure he’d prefer Sessions stayed and was more aggressive. He doesn’t need another nuclear war just to get another AG through the Senate.