I don't think so. A siege is not prohibited under international law. The Palestinians at that point had plenty of water and food. The bar, to me, would be at the point where they're actually starving, i.e. they have used up the entirety of the stuff they stocked up, including Hamas' stocks in the tunnels, and were starving/had nothing to drink, and Israel at that point refused to let any provisions through. This is actually starving the population. You can lay a temporary siege that's well below that bar.
Again, a siege is not prohibited under international law. The civilian population being to leave would be one example. Allowing humanitarian relief would be another. Along the lines of what I said above, the question of humanitarian relief only arises later into the siege when there is actually a humanitarian problem. And Israel reversed course on some decisions and allowed aid even before that. Gallant did not say Israel would prevent Gazan civilians from leaving to Egypt (e.g.).
This was said at the heat of the moment. I do realize it's hard for random people on the Internet to understand the shock Israel was under at that time. It's also fair to expect the minister of defense to moderate what they say. It's also still very much a cherry pick reduced to a propaganda line item.
