I'm not sure what your point about the present simple is; but simple 'have' is used in sentences like: I had an exam yesterday; I have a doctor's appointment tomorrow.
'Incoming' is an adjective here, and is correctly used of things that come towards you: aeroplanes, messages, etc. But when it means "getting closer in time", we use 'upcoming' instead. The exam is coming up = The exam will be soon.
In November I go to Timbuktu.
(Someone talking about their appointments later in the year.)
We usually use the present progressive (I am going) but the present simple is also used with a future implication.