Orders prohibiting divorcing parents from discussing the issues or denigrating the other parent are ubiquitous--they are often boilerplate regardless of whether there's been a problem--there is no REASON for either parent to discuss those issues with the kids. I'd suggest making it applicable to both of you, except that you definitely want to be able to discuss their dad's drinking for the purpose of keeping them safe and to prevent them from thinking any of this is their fault.
And Aries has a good point--who's going to see the divorce papers unless one of you shares them with someone?
ETA: Tell him if he has any issues regarding the divorce to discuss them with your lawyer. That's one of the biggest advantages of having a lawyer--you don't have to discuss anything with him directly.