Why does Thief Mk2 need to be a reboot? Because industrialisation, bitches.
Despite the previous games’ themes of magic vs. technology, there hasn’t been any room for technology vs. artisans. Cogs and levers are too integrated into the setting; you might as well do The People of London vs. Indoor Plumbing. Yes, we haven’t seen any evidence of, say, widespread machine weaving but they can sort out a functional artificial eye, I think they could knock together a clockwork loom.
There is, technically, space for it in the current incarnation of Thief, but you’re gonna need a shoehorn and a mallet to get it in there. In fact, you’re going to need that combo to fit anything into current Thief canon. That timeline’s fuller than Arkham graveyard after a full moon.