Noticed this in other meets, watching the Stumptown Twilight brought it back up again for me. For example, none of the Oregon guys in the 1500 (Haney, Cheserek, Prakel, Maton) were wearing UO uniforms, while Grant Fisher was repping his Stanford kit.
Yorks has been racing in his UW kit in the pro meets he's run so far.
Do different schools have different policies regarding this? Why would they disallow wearing the team uniform?