This is correct. "TLC" is a misnomer. 2^3 is 8, and TLC stores 3 bits per NAND cell, or 8 voltage levels. I suppose when they came up with "MLC" for 2-bit cells (4 voltage levels), which is now also a misnomer as all multi-bit cells are technically MLC, they did not expect to put more than 2 bits in one cell.