The media is once again pretending that a White House refusing to allow officials to testify before an opposition House committee is some sort of shocking new low. In reality, it's ridiculously routine. And the media was fine with it when Obama was doing it.
Here's an example.
Obama Official Won’t Testify to Congress - New York Times
The White House said Tuesday night that it would refuse to allow its director of political strategy to testify Wednesday before a Republican-led House committee investigating whether the administration had illegally conducted political activity in the West Wing...
In past confrontations between Congress and the executive branch, lawmakers have held officials in contempt if they refused to appear.
Presidents have also made formal, legal assertions of executive privilege to keep advisers from testifying.
So this is yet another round in a familiar struggle. But we can expect the usual media and Never Trumper lectures about how this commonplace event represents a new and horrifying low that can't be addressed through any means other than the 25th Amendment.