Bill fly and infrequentflyer, it probably goes at bit further than that. During an active investigation, the participants are under what's basically a gag order - all public information releases should come from the lead investigating agency (or at least be cleared with them before hand). We were not even supposed to talk about it with co-workers who where not involved in the investigation or didn't have a 'need to know'.
Note, this gag order doesn't come from Boeing - it comes from the investigating agency - although it was Boeing's responsibility to enforce it. So FCeng may have been 'reminded' not to discuss things in public (consequences could be pretty serious - up to and including getting fired).
Add to that the pending lawsuits - during the discovery phase of the lawsuits they can (and will) ask for copies of every written communication you had regarding the accident - and we had to keep track of and save everything - especially emails. It got so bad during the investigation of the BA 777 that landed short at Heathrow that I simply stopped writing anything down - if I wanted to discuss something I'd go find the person and just talk.