If you are in the IPEB stage and the Air Force has sent it to the VA to get ratings then you are probably found unfit. You may not get an official letter saying you are unfit but the PEB doesn't usually send your case to the VA unless you are unfit and they want ratings.
Usually, but it depends on where you are in the process. If you are in the IPEB phase, then yes, it means unfit. If you haven't hit the IPEB phase, then no, it just means they received your C&Ps and are working ratings prior to the IPEB. It's there way of prepping and speeding up the process in case the AF sends it over to them during IPEB.