When you migrate the memberships in the first place, the members will keep receiving notifications during the migration. In order to avoid these notifications, you can choose to skip membership migration by disabling the option “Teams – Migrate Membership”. It is Enabled by DEFAULT.

You can choose to Migrate Membership at any later point of time, by following the below steps

• Enable the option “Teams – Migrate Membership”
• Retry the same task created for Migration