Your client is migrating to Enterprise Grid and is looking for guidance on how to...

The correct recommendation is to collaborate with guests through Slack Connect channels . In an Enterprise Grid migration, guest access must be reviewed carefully because external collaboration should be governed, secure, and intentionally scoped. Slack Connect is the better long-term model for working with external parties because it allows separate organizations to collaborate in shared channels while each organization retains control over its own users, authentication, lifecycle management, and security policies. Option A is dangerous because converting guests to full members gives external users internal membership privileges and can create unnecessary security exposure. Option B addresses authentication behavior but does not solve the access model. Option C preserves a guest construct, but it does not provide the same clean enterprise collaboration model that Slack Connect is designed to support. The question specifically asks how to manage guest users post-migration while retaining collaboration access; Slack Connect preserves the collaboration need without turning external people into internal members.

Reference topic: Delivery and Migration — Enterprise Grid migration, external collaboration model, guest-user planning, Slack Connect transition, and post-migration access design.

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