In Book 17 of The Odyssey, what is gained by having Telemachus assert himself when he returns from the challenge?

In Book 17, many suitors are becoming aware of the vacuum
of power that will exist with Telemachus gone. They plot to kill him. Penelope will have
to choose at that point. For Telemachus, several advantages are gained by his assertion
of himself. First, when the suitor who throws the stool at the old beggar (Odysseus)
does so, Telemachus wants to get all fired up right then and there. But by hold himself
together, he demonstrates poise, confidence, patience, and rage withheld. This is
important because that rage will need to be released after Penelope's
challenge.

At this point in the storyline, Telemachus needs
to demonstrate that he is a man to be able to assist Odysseus in the upcoming battle
against the suitors.