Onboard a skeptical engineer to an AI-heavy team

A strong engineer joins your team from a company that banned AI assistants. Your team uses them heavily. Agents draft most routine code, and 3 unwritten norms hold it together: verify before merge, keep the spec in the PR, and never let an agent touch the authorization code. The new hire feels it is cheating and worries their skills will fade.

How do you bring them into the workflow so they are productive without rubber-stamping, and what do you say honestly about the skills worry?