Yeah, even she's doing Perks, I don't think she will announce it directly. She may said something like the quotes from Cinemania interview but won't tell us which movie she would be in. But we could get the truth from candids and other info channels
Well we don't know exactly why Emma didn't publically announce her role in My Week With Marilyn. It may have been by her own choice or it may have been something she had to agree to. Since filming for Perks apparently begins in December it won't be long before we find out for sure.