Purposeful, perhaps, or maybe nothing more but a political ploy to keep his base and the rest of the country focused on him. The MSM doesn't seem to be making a big deal out of it.
Talks about him draining the swamp and Barr saying that he'll do the same haven't panned out - not even close. It's been a major disappointment. Not holding my breath that this is what he meant.
My hunch is that this is nothing more than he needs a break before the debates and election day. He needs time to sit back and assess all that is going on and contemplate and calculate what he plans to do next.
My other guess, is perhaps he's even thinking of stepping down. I wouldn't at all be surprised.