Operator Approvals

Every contract you've granted permission to move your tokens. Listing on a marketplace adds an operator approval; cancelling the listing does not always remove it. Stale approvals are a security tail risk — anyone who finds a bug in an old marketplace contract you're still authorising can drain that token.

Revoking will mean if you re-list later, the marketplace will need a fresh approval. That's fine — it just adds one extra signing step.