It looks like you can still withdraw:
https://www.nobsbitcoin.com/gemini-uk-to-prohibit-regular-bitcoin-transactions/

"When depositing or withdrawing from your Gemini wallet to another crypto address, we will need to request additional information from you, such as your name, the beneficiary of the funds, and in some cases, your address."

Odd that they need to KYC you again for withdrawals since they already KYC'd you to get onto the exchange.