Gravel up to extension; am I putting the foundation at risk?

Hi brownstoners, I’m worried about some work and would really appreciate your thoughts. We have a very small (about 9 x 12) shaded area immediately behind our extension. We are installing a deck over only that area, and in doing so the builders removed the existing concrete and drain and plan to leave only (very free-draining) dirt and gravel underneath. The other portion of the yard, which is also very small, remains bricked over and graded to a channel drain, or planted. The area is also adjacent to a retaining wall for the neighbor back behind. So this is a very small area to begin with, and in general I like the idea of less concrete, but I’m still nervous that it’s a bad idea to have any moisture going through the dirt that abuts the foundation. When I asked about it they said they could grade it toward the back and do a french drain there. In general I feel our weather is only going to get worse and want to plan to handle more water, not less. Does anyone have any thoughts? Thanks so much.