Tom - I think, as TPA's, we probably all know in whose lap the responsibility is likely to fall...
Now it is time to rant a little bit.
My own feeling is that the DOL should require only a website URL/LINK on the statement that refers them to the DOL website for the calculator. Then the DOL can have whatever assumptions they want on the calculator, as well as any disclaimer language, and the statements can have just a canned statement, developed by the DOL. This stuff about requiring the payment amounts on the statements is utter foolishness, and in my own cynical view, is being pushed (under the guise of helping participants) by those who have or will obtain a financial stake in lifetme payouts, as well as some well-meaning but sadly misguided do-gooders. I hasten to say that I have no evidence whatsoever to back up my cynicism.
The simple fact is, whether you like it or not, that most participants in DC plans don't want, and will never take, a lifetime monthly payout option!
Rant over. For now.