I agree that the announcement may have been slightly misleading 
sorry to hear that you did not yet receive the update. Hopefully it will soon come through 
I would also suggest to check out the FAQ here:
Q: When do I get the Update?
A: We are providing the Android 9 in batches - each with a limited amount of users, starting on March 25th, 2021. We expect that all devices still in use shall have received the notification for the update in May, 2021. This controlled roll-out enables us to quickly react to possible bugs and issues that arise in the field.
and
Q: I did not get the update notification yet. How can I update now?
A: You will have to wait until it is your turn. When that time has come, you will receive a notification on your device and you can follow the instructions given there. A manual update to Android 9 is only available after we have invited all Fairphone 2 users to update.
If you can not wait to use Android 9 on your phone, you can always consider joining the beta program. Otherwise you will need to be a bit more patient I am afraid.