The page already has been taken down but yesterday the 860 Pro 4TB surfaced, today the EVO edition says hello to the public. The page showed both a 2.5" version with a maximum capacity of 4 TB and an m.2 form factor SSD of 2 TB.
The content has been taken offline again. The M.2 models will become available in versions of 500 GB, 1 TB, and 2 TB, while the 2.5 "also sees a 250 GB and 4 TB model. The 860 EVO offers sequential transfer rates of up to 550 MB/s and up to 520 MB/s sequential writes, up to 97,000 IOPS 4K random reads, and up to 88,000 IOPS 4K random writes according to the product page.
Samsung mentions V-NAND, likely new 64-layer one. Back in October the SSDs already appeared in various databases as well. Also mentioned is that this new-generation flash has been rated for "8 times higher" thus better endurance than the 850 EVO series; with up to 2,400 TBW, for the biggest volume size SSD.
The new leak indicates a launch, very soon.