You have a big invitational on a Tuesday? That seems kinda odd. Are you sure it's not a dual meet?
I'm not your coach but perhaps he really wants to see what kind of top end speed you have. Or maybe this is a workout or a test to see how you run with some lactate in the legs. Maybe your just an experiment or maybe he's clueless. Whatever it is you just run hard.
Why come on a message board though? Why not just ask him directly? I am always open to my athletes thoughts and more than willing to explain if I want them to run an off event.
Btw, I ran a PR in the 5k after doing an 800, 400, 400 @ 2 mile pace 15 min before my race. Coach wanted us to run tired but it woke up my legs and probably led to a good warm up on a cold day. Anyways, just run man.
But I still don't think it's an invite.