I wouldn’t be so sure about that. You can easily reuse walking animations and show them from all angles, but special animations need to be made as they do in 2D.
And we are talking about TWP-style graphics (low-res pixel art). I’m sure someone like Octavi is quite efficient now with animating those characters. How fast professionals can animate rigged 3D models depends on the complexity of the model and how much work you want to put in it to make it look realistic. Also in 2D you can easily do additional special art, like letting Reyes’ tie fly around which in 3D would mean a lot of additional work.
Nonetheless if you want to do a 2D game in HD then 3D is often the best choice to help you with having detailed and fluid character animations.
A very early example of such 2.5D approach being Grim Fandango with 2D backgrounds and realtime rendered 3D characters, another example is Broken Sword 5 with 2D backgrounds in HD and 3D characters prerendered to 2D HD sprites.