In light of today's horrid employment report I have my doubts. I see two separate classes of concern:
My best understanding is banks must pay the APY originally agreed to. Should they become unable to do so, they go out of business and you get your money back. At that point, of course, you have lost your existing interest rate.
Most credit unions have an umbrella escape clause, virtually never invoked, which gives them the right in effect to change CD rates under extraordinary circumstances.
Given conditions in Europe, and given today's shocking jobs report here, all I'm saying is that I'm no longer counting on my existing CDs to "go the distance".