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, blockexploreres 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 regard, your question is "
is an address created once it received bitcoins?" in a sense that 'the Bitcoin World' is what people see.
By disregarding the network, try to type any unused
valid address to any
blockexplorer and it'll "
find" it since addresses have always been existing.
Additionally, the first transaction related to address:
11111111111111111111BZbvjr representing the number '1' was on 2011.
But that doesn't mean that number 1 or
11111111111111111111BZbvjr is created on 2011.
Because every address that represents
HASH160 value of
0x01 to
0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF have always been existing.