Except that it did. Slave owners in the border states and a the regions excluded from the EP by virtue of their perceived loyalty were compensated when their slaves enlisted because the Takings Clause of the Constitution prohibiting the taking of property without compensation. Under the 1st and 2nd Confiscation Acts even slaves in those areas could be taken if they were used if their owners supported the rebellion. If a loyal owner in one of those areas lost their slaves they may of had a claim against the Federal government. Slaves in the regions covered by the EP were considered in rebellion and the slaves there freed, regardless of their owners professed loyalty. No, it did not have an immediate effect, but whenever slaves in those areas came in contact with United States troops, whether by escaping to them or being reached by their advance, their owners claim on them had been extinguished. It really doesn't matter whether the CSA recognized it or not, it was their status under United States law that mattered. If the South had won its independence it would have been a moot point anyway, but if the Union was restored with slavery intact it could have become a major issue. Of course in the long run the 13th Amendment eliminated all such issues, which is why Lincoln pushed for it.