Not just the same amount of CUs, but equivalent CUs as well. Equivalent ROPs and memory controllers, as well. It's not the same Pitcairn found in PCs in its physical arrangement (due to being in a custom APU with some of the modifications found in Bonaire and Hawaii), but this is not next-gen GCN. There haven't been any changes to the CUs resulting in any measurable changes, just some changes also found in contemporary and even older GPUs still on the same fabrication process with the same core design and performance per clock. Math supports this. We're probably just getting into a semantic debate about what constitutes the same core, otherwise, but its actual cores (shader cores) seem completely identical.
For example, the reference 7850 has 16 GCN compute units clocked at 860 MHz resulting in 1.76128 single-precision TFLOPS.
The PS4's GPU, though not having quite as an exact of a figure being available, has 18 GCN compute units clocked at 800 MHz resulting in 1.843 TFLOPS.
800/860 = 0.93023256
1.76128 x 0.93023256 = 1.6384 TFLOPS (the value of 7850 at the same clock speed as the PS4's GPU)
18/16 = 1.125
1.6384 x 1.125 = 1.8432 TFLOPS (the PS4's single-precision floating-point performance calculated purely from 7850 values).
1.8432 = 1.843
Therefore the CUs of the PS4's GPU are exactly identical in single-point FLOPS values as those of Pitcairn. In light of that along with the otherwise identical major specs and fabrication process, it is extremely unlikely that the PS4's shader cores or CUs in general are any different than Pitcairn's. Any differences in general are relatively minor and more related to increased efficiency within the architecture rather than any fundamental changes. There are modifications certainly, but Pitcairn is pretty comparable.
Besides the people who have read the books and just don't like Yennefer, of course.
