Mueller reportedly has said he *wants* to testify. And the reason he wants to, at least according to the report I saw, was that he thought Pelosi was out of line for accusing Barr of lying and he wanted to clear some things up. So if the House wants him there, and he wants to go, and if Barr doesn’t put the brakes on it, then it seems likely that he will testify.
Well I was thinking it was an article but it was really just a tweet by Jack Posobiec:
https://twitter.com/i/web/status/1124116036272496640
“BREAKING: Special Counsel Mueller “deeply disturbed” by Pelosi accusations against AG Barr today and is urging Nadler to push up his hearing to testify and correct the record as soon as possible - @OANN”