M365 tenant to tenant migration - Users membership to external teams

[Gurdev Singh]

For a M365 tenant to tenant migration where the domain is also being migrated, what will happen to users membership of external Teams where the user is a guest member.

E.g., Sarah@contoso.com from Contoso is a member of a team from tenant Tailspin. Contoso tenant is migrated to Fabrikam including the Contoso domain which means Sarah's username and email is still the same. Will Sarah continue to be a member of Tailspin or will she need to be re-invited.

[#2]

I believe you will have to be reinvited since you’re not authenticating against the same tenant anymore!

[#3]

Thanks, Adam...I think the same i.e., I am 90% sure that user will need to be re-invited as user's home tenant would change during the domain migration process. However, it's very hard to test and I wanted to be 100% sure before I tell our business stakeholders. Any Microsoft guys here.