The extent to which designers have come to feel entitled to be distant from the whole of the work involved in building a software product is a much bigger problem that needs to be solved. Don't pander to any designer's expressed right to not have to know how their work gets integrated into the whole.
The kind of stark specialization that has grown up in the designer community is one of the biggest industrial maturity problems that faces the software development industry. It's an extent of specialization that predictably creates more rework and longer cycle times.
This is also true of developers' sense of entitlement to go blissfully unaware of interaction design and implementation.
Extreme specialization is always an exponential multiplier in productivity problems. Solve it organizationally by adopting processes that promote learning cultures. This is the level of maturity that most other production industries have already realized, and that software drags woefully behind.
At every place in a development workflow where handoffs occur between over-specialization, work queues and buffers form. Software remains one of the few industries that doesn't recognize this as one of the biggest problems we face. This is even more exacerbated in the Microsoft community as over-specialization seems ever-more normal due to Microsoft's perpetuation of over-specialization through its tools and guidance. Unless you can afford to waste as much money as Microsoft does in development efforts, you should look to methodologies that are much better informed on questions of flow and productivity.
Consequently, the developer who cannot test and the tester who cannot code is a symptom of the same industrial immaturity.
You won't learn any of this from the Scrum template for TFS. Microsoft was years behind the curve in getting agile thinking in-play even in its most rudimentary forms, and now that we're progressing into Lean thinking, Microsoft will be another three to five years away from trying to incorporate Lean thinking into its product lines. Don't wait for Microsoft to tell you how to shape a team and a workflow. You can learn right now from the people that Microsoft will ultimately pay attention to in a few years.