You might be surprised to know that certain large customers are in programs with Microsoft called TAP (and RDP, thanks @bill, but way to go Microsoft on recycling yet another acronym). And they are certainly coached and supported in going to production with CTP releases, coordinated with the support team of course (nobody can go to production without hitting certain milestones and meeting certain requirements). This isn't Stack Exchange independently going, "hey, let's kick the tires on this beta we just downloaded."
I can assure you beyond a shadow of a doubt that if they're moving a current build to production, they have Microsoft's full support and undivided attention. Due to NDA I can't really speak much more to this, but your fears of things going wrong and Microsoft waving a big middle finger to this site are completely unfounded and have no chance of ever happening. Now, if you were to try to take your evaluation edition to production, you'd be on your own (and in a heap of legal troubles if you were big enough for them to care).