It will, but you'll void your warranty, and it's annoying that Lenovo doesn't offer it themselves – all their notebooks are built to order anyway, so they're actively hurting themselves by artificially constraining their customers.
The T460p has fully expandable RAM (almost 5 pounds), but it's a lot bulkier than the other variants (but somehow has smaller batteries), and for inexplicable reasons uses inferior materials. (Pure ABS plastic like on L/E series Thinkpads, not fibre-reinforced.)
Lenovo's model policy is somewhere between "annoying" and "fucking insane", every laptop is seemingly made by a different team and none ever talks to each other.