Updating an ERC-721 Claim Edition Size

I set up a limited edition erc-721 claim page with an edition size of 50. All tokens were minted with serial numbers i.e. 1/50,2/50, etc.
If I now update the edition size to 65, what would the numbering of the 51st token be?
Will the tokens that are already minted need to be manually updated?

If the claim is edited - The next token should be 51/65!