You should mention that you are talking about p2pkh outputs
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The public key is only published when a transaction spends funds previously sent to that exact address.
Only after an address has spent money can the public key be recovered from a transaction stored in the blockchain.
Not only. Let us take the genesis block and its coinbase transaction
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Well, you answered the OP's first question as "yes" (as long as that user is Satoshi). Not news to me, but informative to others:
The original generation of 50 BTCs from mining was a pay-to-pubkey script.
OP hasn't really revealed a topic of curiosity though, unless you want to send someone unsolicited op_checksig payments.