Even if it's a marketing strategy, it's one that will certainly gain a lot of attention from people in the crypto community and among all Bitcoin enthusiast.
It works for HBO this way and they are happy with effects from their documentary film. It's all they need, fact or not fact attached in the film, they didn't care.
It's a documentary at the end of the day. They might try to compile some research and interviews they've done that sends a pointer to who is likely Satoshi based on some evidence and some likely footprint he's left behind.
Many documentary films can be made but fact is very hard to reveal and represent it fully as it is. Half of a fact is no longer a fact, and HBO film can not have even half of fact.
Satoshi Nakamoto is seriously with privacy and anonymity so it will be magic if HBO can figure it Satoshi Nakamoto's real identity. You see, they tried to find it through the forum, while many forum members failed to find it for many years. It is very not logical.