In an ideal world, yes, maybe warm plates. But if I'm serving some sort of huge complicated meal, it's not the end of the world if teh plates aren't warm.
My ex MIL felt differently and once kept us waiting at the dining table, with the food on serving dishes, in my house, while she faffed about in the kitchen warming plates. So we had cold food on warm plates. (I admit I may have got to the end of my tether with her that weekend and may have allowed some PA irritation to take over.)