Executive privilege here flew away a long time ago, and Trump can't get it back. He waived it when he didn't raise it during the investigation.DOJ tonight setting the expectations for Mueller’s testimony. All the reasons the letter says he can’t answer certain questions:— Shimon Prokupecz (@ShimonPro) July 23, 2019
Law enforcement sensitive
Attorney Work Product
Presidential communication privilege
"Deliberative process" refers to government discussions in formulating policy. I have no idea how that applies to Mueller's investigation.
Attorney work product might apply to any work done in the conduct if the investigation, but all that product is presumably contained in the report itself. Same with anything "law enforcement sensitive."
The last "privilege" is just one Trump made up. It also doesn't apply in the context and even if it did (or existed), it was waived a long time ago.
The legal term for all of this is "squid ink."