Entirely possible. I dont know enough about movie metrics to really be able to guess how a Golden Age Superman movie would go over with people.
But we've seen that unconventional comic movies can work. Logan, Deadpool, Venom, etc. We also know that superhero films set in a particular era can work, as we've seen with Captain America, Wonder Woman, and Captain Marvel. And since people know Superman has been around forever they're probably not going to be confused by the choice of setting. It's a period piece Superman movie; not a hard concept to work around. The challenge would be getting people interested.
Plus, there's plenty of us who still remember the old Fleischer cartoons (I used to watch them in the 80's as a kid). And a lot more who are at least passingly aware of them.
I think audiences would be caught off guard by "Superman: The Golden Age" but that might be a good thing too. It might make them curious. And if the general audience looks at Superman and sees a hero who is old fashioned and/or out-dated (which seems a common complaint among the GA), this might even work to DC's advantage; Golden Age Superman can't be out-dated in his own time period.
The power levels being so low helps keep the budget down, meaning the film doesn't have to break a billion to be considered a success.
Personally, I think it'd be worth the gamble. But its not my money and I love the old Golden Age stories, so I have a pretty big bias.
I say look at Morrison's opening Action arc. That was Golden Age Superman done with a modern sensibility and it seems to have been pretty popular. Comic sales and reviews aren't a great barometer to judge by but I consider it a good sign. If the Golden Age inspired t-shirt Superman found success with comic fans (and he did, until DC burned that goodwill) then its possible that a Golden Age Superman movie could be successful too.