Would Satoshi Nakamoto hide some private key with stored bitcoins hidden in this or another forum? 
Private key should be stored safely and in secret. Offline is a must to get good safety. Do you think the creator of bitcoin does not know what is the best to secure his bitcoin's private key when he coded it, launched the bitcoin network years ago?Be your own bank with your private key is the slogan of bitcoin. He would have never put his belief on any online services, forums to store his private keys.
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It would be interesting if he did 
Never. He would have never made such things.