While in our view it's always good drafting for Parliament to expressly articulate the mental element for particular offences, there are certainly examples in the Criminal Code of offences that don't have a particular mens rea articulated. The Supreme Court has made clear that when we're in the domain of criminal law, even if Parliament hasn't seen fit to articulate what the mental state is, the courts will determine what mental state is required, but it wouldn't be possible to convict someone who didn't have some blameworthy state of mind.
That said, though, sometimes one of the things we look to is the action verbs in a particular offence. Sometimes action verbs imply a mental state in and of themselves. It's difficult to conceive of someone promoting something or receiving money for something when they didn't know what they were promoting or what they were receiving money for.
There's a good argument that “knowingly” for sure makes the law clearer, but without “knowingly”, the sorts of action verbs that you have in this offence imply a subjective, knowing state of mind in any event.