I'm happy for the Sysinternals crew. They had a great opportunity and went with it, but sadly no more source code.

From the licensing FAQ:

Q: Can I license or re-use any Sysinternals source code?
A: No. We will no longer offer the Sysinternals source code for download
or license.
---
Q: Will Microsoft migrate and host all the Sysinternals tools?
A: No. A small number of tools were identified for removal before the
acquisition. We worked very closely with Mark Russinovich to determine
which tools to migrate. That said, a majority of the tools will be
migrated which include the latest and most popular tools. In addition,
we will be open to resurrecting old tools based on community requests.

Dean