I will have (past participle of verb) (object) is English's "Future Perfect" tense construction. It refers to actions (on the object) that you will complete before a certain time in the future.
I will have (object) (past participle of verb) is a construction that in English means "I will direct that the object be (verb-ed)".
I will have the package sent by next week
is acceptable, and means that before next week, you will have arranged for the sending of the package.
I will have sent the package by next week
is also acceptable, and means that before next week, you yourself will have done the sending of the package.
By next week I will have discussed the project with the professor and would be able to answer your questions then.
is acceptable and means that before next week you and the professor will discuss the project.
By next week I will have the project discussed with the professor and would be able to answer your question then.
is unusual. It might mean that before next week, you arrange for the professor to discuss it with someone else (not you).
We can use the present for scheduled events in the near future. However, we don't use the present at the time we are scheduling the events.
The sentence
My friend will pick you up at 4:00.
sounds to me like I am informing the listener of the arrangement. In this situation I would use will pick you up rather picks you up, I think because I don't consider the event to have been scheduled until the listener is informed.
On the other hand, if the listener already knows about the schedule, and we are just confirming the arrangements, I would use picks you up.
And in situations like the concert starts at 7:00, I would use the present tense regardless of whether the listener knows already, because this event is scheduled even before the listener is informed.
Best Answer
Will be discussing this would work. There is some time in the meetings next week when we will, in fact, be discussing this.
Either will discuss the matter or will have a discussion on the matter is correct. But they have slightly different connotations: will discuss could span some time, while will have a discussion refers to a particular discrete event.
Will be discussing on this, as you have said, is incorrect.
There's another issue here which you have not asked about: a native speaker would be rather unlikely to say that a meeting will discuss anything, since it is not a person. The phrasing would more likely be we will discuss this in the meetings, or perhaps the meetings will include a discussion on this, or something to that effect.