I currently presume that when someone initiates a transfer that results in coins being deposited in address X, this is when address X is first instantiated, when it first becomes part of the BTC world. It is when the BTW world first becomes aware of that specific address.
Is this a valid statement?
Not technically, as explained in the first two replies.
In the Bitcoin Network, those coins aren't deposited to an address but a newly created UTXO, there's no address saved in the network.
That statement only applies to "
Bitcoin World" in social media, forums or wallets where address is a thing.
"
Wallets" included because it is a separate feature than the network. It hodls keys, creates transactions and fetches UTXO that its keys can spend.
This is why I've put question to your definition of "
the Bitcoin World".
So in that regards, your question is "
is an address created once it received bitcoins" which can't be answered since there's no address in the network.
It's more of a "
what you people think" than an actual technical question.
The most accurate answer you can get is every address have always been existing since it's just a human-readable representation of numbers which always existing.