Hehe, well done!Instead of wondering, I conducted a test. It appears that the bracket and fan hold up well despite the unrealistic force. However, since the product is in the prototype stage, things can still be tweaked and improved. I will be posting images with different hardware configurations soon.
But...
there is no weight on the prototype and thus it can 'follow' the fan displacement.
As you say, there could be a little improvement here, but anyhow things look already sturdy!