Suggestion for Book of Lairs

I’m guessing there’s a good chance its already planned, but something that would be helpful to have is a breakdown per monster of languages they may speak, and the chances thereof of any one specimen speaking that language. I’m assuming that some orcs speak Common, for example, so I’ve been assuming a % chance during encounters on the albeit rare occasions when players want to parley. Is this something y’all have given some thought?