If you have installed the MyCompliance Microsoft Teams Integration for your organisation, and have either added a new user to a campaign/course/policy manually (or done automatically done from our syncing mechanism), then Yes.
Any new user who has been updated as a target will see all published courses and policies through their Microsoft Teams Integration, regardless of the dates set by a campaign for notification purposes.
This means they can complete their training ahead of schedule, and there is no way to stop this due to the content being in a 'published' state.