You have no idea whether he is making videos for Canon or not. He has the equipment on loan for 3 weeks is all we knowI think you are missing my point. In the context of the conversation, he has three weeks to make videos for Canon (not with Canon equipment) then the implication, though not mine, was that those videos were going to be used by Canon as part of the release of the R3. If that is the scenario being talked about he does not have free rein, he is being paid by Canon and he does not have editorial control, the customer, Canon, does.
If he is going to release the videos on his channel then yes, within the bounds of good business sense and relationships, he can say what he wants. But that isn't what we were talking about, we were talking about a time limit with a preposition that this videos were for Canon. After all, he wouldn't have time limit on a personal video release.
However my point was if that is the case you still can't draw release date information from him having the cameras 'for three weeks to make videos', it is simply too vague. We don't know if the videos are for his channel or the Canon channel, we don't know if he has to return the cameras in three weeks so they can go to other testers pre release, we don't know anything more about a release date from what was said!
But we do know that he does not have editorial control over commissioned works by Canon, only his own channel output, they are different and we don't know which he is shooting for or indeed if he is shooting for both (most likely).