He appears to be playing fast and loose with the news media - NBC will broadcast a pop-up town hall meeting on Thursday (opposite the Biden event scheduled last week after the debate was cancelled). They need assurances that he is no longer contagious; the test results the White House has provided are one that can be manipulated to show he's okay without his actually being completely okay. Any other test results in a sequence of tests they refuse to share. I don't consider Savanah Guthrie a powerhouse moderator—she suits the Thanksgiving Day parade very well though, so perhaps she's perfect for the Trump event.