I am using binance and Kucoin and as I remembered more than 3 years but still not asked for KYC second time but 2 days ago I experience problem with OKX which ask me to do KYC again and unfortunately I lost my ID card in my home and I don't remembered it. In my country we have to wait for one month to get new card.
Centralized exchanges and similarly gambling sites can ask you to resubmit KYC documents to verify your identity again.
Your situation is not actually bad because you used your own documents to verify your account. 1 month is not too long waiting time and you are lucky because the market is before a bull run. It will be worse if you fall into this situation but when the market is nearly its all time high, if you stuck one month, you will lose a lot of money.
This situation will be nightmare for people who bought accounts or bought identity documents to verify accounts. They will not be able to do this again, for second, third time or fail if exchange asks them to do advanced KYC like video verification.