Is there a way to set up TFS code reviews to be assigned to a random team member?
The motivation for this is that I believe that the team members often assign someone they discussed, or even pair programmed, a problem with. That reduces one of the benefits of code review, namely the spreading of knowledge. Some team members always select a colleague they're close with.
I do realize that there could be issues with the assignee being busy or out of office, but there might be other solutions for that.
I am currently on TFS 2013, but if it is possible in other versions, that is still of interest.
This could not be achieved for now, you should manually add reviewers.
And it's also hard to random assign the code reviewers. There are many limitations, some you have mentioned above. Another important thing, it's hard to determine whether the code reviewer have enough ability or familiar with the area of code under review.
A more easy and valid way is sending the review to a TFS group.Each team has at least a few senior developers that do code review on a regular basis, and you could set a rule such as a code review must be reviewed by two or three reviewers. However it's still on the backlog and there has been a related uservoice. You could vote up and monitor it.