Odd that it's not accurate, as it was only updated earlier this year. But if that's right and you need to wait for them to schedule the appointment for you, I think you may just be expecting it too early. Lagos has long wait times (over a year for other visa categories).
If the medical examiner told you that an appointment letter is needed, that's right, but doesn't mean he doesn't schedule it himself.
Has he had the biometrics/document review appointment yet?
Other threads on here say he needs to schedule the main interview himself so might be worth posting in the relevant country forum to double check -
Good luck.