Yes, in the same way that an excellent front-door lock doesn't stop someone from smashing your front window. For the purposes of encrypting traffic to prevent

Yes, in the same way that an excellent front-door lock doesn't stop someone from smashing your front window. For the purposes of encrypting traffic to prevent eavesdropping, one of the recipients sending the unencrypted data to a third-party is not an attack vector of consideration. In your scenario the only viable measure is to send no data at all (aka "don't play").