it's also possible that OP just made a deposit of Luna into the exchange using his Luna deposit address that he already has saved somewhere.
I didn't consider that because I would personally never do something like that without checking my exchange account first. Not just to see if the deposits are still allowed, but also to ensure that the address hasn't changed for some reason and that my account is still on good condition (no limits, suspensions, requests for KYC. etc.).
The thing is, do we know for sure this didn't happen?
No, not really. I didn't consider the possibility which Bitcoin_Arena brought up that the OP could have saved his deposit address somewhere and just deposited the coins to his account without checking the exchange and the status of the Luna blockchain.
We will know more if we see similar accusations by other users against Gate.io.