I don't see the point. If they anticipate 51k FSW principal applicant's entering in 2015, there should at least be a proportional number expected for 2016.
Looking at CIC's history of all of these programs and progress each year, there has not been a dramatic drop any year and so far there is no reason to anticipate one.
So the expectation that number of ITA would go up significantly towards the second half of the year, high enough to cover majority of people without PNP or LMIA based jobs is very realistic and there is no reason to believe otherwise.
They might not be 51k, but even if they are 30k - that is still far too higher than would be covered by only LMIA or PNPs