The exchange will not notice it unless the person do KYC itself admit it to them. Remember that the change don't have any legal documentation coming from so there's no way for them to determine if you are the original owner or not. Even if they try to detect your IP. There is always a VPN to cover that.
They might. I'm not familiar with the sign up process for Crypto-Bridge, but many exchanges that do not require KYC (not that there are many left), still require a name, email address, country, and sometimes an address. If you have signed up as Robert Paulson with
robert.paulson@gmail.com with a US address, and then complete KYC with documents belonging to Monty Python at a UK address, it's going to raise some red flags. Very likely your account will at least be suspended pending further investigation.
As I remember clearly. Signing up on exchange didn't required any personal info in your account. Only email and password. But of course case to case basis. And as I visit crypto bridge registration site. It really does not require any personal information during registration process. Actually this is the essence of crypto. To trade anonymously that's why most unregulated exchange don't ask personal info.