They're not mentioned very often, but it looks like at this point for the T4xx you have to go with the "p" models to get a Nvidia GPU - the T460 and T460s are only Intel, as I understand it the T460p is somewhere between the T460 and the W product line - a little bigger, a little more expandable, etc.
Looks like you can also only get the GPU with the i7-6820HQ, so out of all the T product line there's a single CPU/GPU combination that's not using the Intel graphics. That may in part be related to the significant improvements in Intel's graphics capabilities in recent generations - starting around the HD4000 in the third-generation processors the GPUs are actually reasonably capable, and they've improved rapidly even from that point.
Looks like you can also only get the GPU with the i7-6820HQ, so out of all the T product line there's a single CPU/GPU combination that's not using the Intel graphics. That may in part be related to the significant improvements in Intel's graphics capabilities in recent generations - starting around the HD4000 in the third-generation processors the GPUs are actually reasonably capable, and they've improved rapidly even from that point.