Do these tops need reinforcements?

I’m currently working on building a set of nightstands with slab tops (kiln dried walnut, taken from the same slab) and was planning to inlay some steel C-Channel underneath in order to keep things from warping. Given the size of the slabs, do people feel like this is a necessary step? I’ve already seen a little bit of warping after the first round trimming and planing the slabs, but after flattening a second time they seem to have stayed static.