Apple's public documentation doesn't explicitly guarantee whether the Team ID or an existing Developer ID certificate stays the same and active after an individual-to-organization conversion. Apple describes this as updating your existing membership, and says a Team ID is assigned to a membership, so I would expect the account to remain the same, but I wouldn't rely on that assumption for a signing or release plan.
Before proceeding, ask Developer Support on your conversion case to confirm both points in writing: whether your Team ID will remain unchanged, and whether your current Developer ID Application certificate and signing identity will remain usable. Don't revoke the certificate yourself. Keep a secure backup of the certificate and private key. Apple notes that revoking a Developer ID certificate can stop users from installing or launching software signed with it.
Apple's conversion instructions are here: https://developer.apple.com/help/account/membership/updating-your-account-information/
Team ID: https://developer.apple.com/help/glossary/team-id/
Developer ID certificate behavior: https://developer.apple.com/help/account/certificates/create-developer-id-certificates/