Hi Katrin,
If two players were mutual friends before the update, and one player updates to the beta. They will still be able to send each other Koi. If you see "Friend Expired" it means that you two are not mutual friends on the old system (They must have removed you from their list). We hope to seek your understanding, that in future when we roll out this update, all players will be able to gift each other. Please note that this is an opt in beta test, you may leave the programme if you wish to use the older version in the mean time. Thank you for joining us on our testing journey!