I'm here now as well...no language requirement, but taking a language is optional in the afternoons (outside of the normal class schedule). They told us that they would put something nifty on your training report like "followed CSAFs vision with advanced language program," for whoever partook. But the languages have no grading or quantifying criteria other than sitting through the class, or at least as many as you would like to attend. Either way, its nice that the instructors are available for those who want to pursue, but it is not needlessly forced on everyone.
As far as the language requirement, I think the DLAB is mainly for applying to certain foreign schools through the 3849 process, rather than ACSC itself.