This would certainly be a welcome development, as very often nowadays manufacturers ship their phones with combined SIM/microSD slot, forcing you to choose between using a second SIM card, or having enough storage for your needs, which oftentimes results in buying the more expensive version with the higher internal memory level.
As for the specs, we can only be guessing for now - the original Huawei Enjoy that was announced back in October, is a pretty unassuming device, with the only stand-out feature being its massive 4000 mAh battery. Some are speculating that a Huawei ABC-UL00 device that was recently logged in the GFXBench database, is precisely the Enjoy 5S. Previously it was thought that the ABC-UL00 coding denotes the Honor 5X, but the announcement of that one came and went, and its specs have little to do with what's in the benchmark's database.
If Huawei ABC-UL00 is indeed the Enjoy 5S about to be unveiled on Thursday, then the phone would arrive with a 5.2" 1080p display, Kirin 935 chipset, 3 GB of RAM, 13 MP main camera, and an 8 MP selfie-snapper. The icing on the cake is the 64 GB internal memory, though the model tested here might simply be the one with the highest storage amount.
All in all, it's not hard to imagine such an Enjoy 5S by Huawei - after all, its Honor 7 has very similar specs, with the exception of the camera that is 20 MP. If the metal Enjoy 5S carries over the big battery from the Enjoy, it will only be a plus for the handset, and set it further apart. That also depends on the pricing, of course, but that's a mystery we will have to wait a day or so to be solved.