You're not giving them 6 months. You're giving them 1 day, before they may end up even seeing the email and getting charged against their will. Even if they do see the email, 1 day is not enough for a change of service notification that would require a migration.
This is disgusting extortioniate behavior that would make me reconsider doing business with Vercel.
This is disgusting extortioniate behavior that would make me reconsider doing business with Vercel.