I dont even know what point you're trying to make. You said I have no clue about the impact of the portal opening, I give the reasons why it doesn't matter when you open, and in your own roundabout and slightly troll-like way, you essentially agree with me.
Coaches can basically talk to players whenever, and players can leave whenever they want. Whether they do those things or not are irrelevant of the portal opening. If they only plan to leave the team after the season ends (which is what happens in nearly all cases) then an arbitrary opening date doesn't change the plan whether you make it March 1st or August 1st.