This is not speculation.
The reason is because the design and cleaning team have all been very successful in their real lives. NOT finances. Babies, far away opportunities, huge new job appointments school, etc. are all going to be taking their toll on the ability of the staff to be at rehearsal, and provide the members with a top quality show and education. The director feels it would be a disservice to the members to hodgepodge a season together.

here is the most relevant part of the email.
What has made Redline unique, and great, is our commitment to making the tough calls. Our determination to always do things on our terms, and our ability to carry out that intent. So rather than taking the chance that Redline could fizzle and die, rather than attempt to be bold under unsure circumstances, rather than force something that may not be intended to fit, I’m making the call to keep Redline’s future firmly in our grasp and take a season off to do what we need to do. While this is difficult to take for all of us, It’s important to keep in mind we’re doing this for the right reasons, one of the most important being that we still have the ability to choose. Most groups aren’t so lucky. Given a year to re-center and continue the search for some new blood we have the best possible chance to re-vitalize and continue down our current path of success.

That's very surprising. That's really too bad, I knew people who marched there. Hopefully Northcoast and Eastside will have plenty of spots for them all.

As disheartening as it can be to see an upcoming powerhouse do something like take a season off, I'm fully confident that a group as well-composed as Redline will surely be back in 2013.

On the brighter side, other groups in the region will surely benefit from the talent brought by Redline members seeking other ensembles.