Yes, I've been recommended to do so. Since I've interviewed at one but am still waiting for their answer and then have two more interviews lined up in March I put all 3 schools down on my FAFSA so they can receive my info. Some schools want you to file your FAFSA by March 1st so I'd say go ahead and just have the schools get your fin. info even if you're still waiting for their answer. It'll (hopefully) speed the process when you do get accepted, plus I feel the sooner you file and they receive your info the sooner they can look into how much $$ they can award you.
Best of luck!