No. As you add gas to the drysuit during a descent the gas volume within the suit should remain constant. When properly used the drysuit doesn't supply any more buoyancy at 100 ft than at the surface.I too disagree on the suit for buoyancy issue. When decending with an empty BC/Wing, one will need to add air to the drysuit to prevent squeeze and provide warmth within the first 10meters (and again as the dive progresses deeper)...this air serves double duty as it also provides buoyancy. There should be no reason to add air to one's BC/wing when one is already adding air to prevent squeeze and create warmth.
While it is possible to do this and make it kind of work with a single tank, it is not optimal and leads to bad habits that often have to be unlearned later. With a single 80 ft^3 tank you only have about 6 lbs of gas weight so it only takes a little extra buoyancy from a BC (wing) and/or drysuit to balance out the gas weight. You can add that much extra gas to a drysuit without causing huge problems, although it does increase the risk of an accidental feet-up rapid ascent. Much easier to just squirt a little gas into the BC and then gradually dump that out during the dive as your tank empties out. While this does mean managing two independent buoyancy sources this becomes super easy second nature after a few dives.The BC/wing should be used for buoyancy if/when there is enough air to prevent squeeze and allow for thermal comfort but the diver requires more air to maintain neutral buoyancy....in this case, typically minimal air will be required to be added to the BC/wing...if a lot of air is still needed to become/maintain neutrally buoyant then the diver is overweighted and/or the diver is losing air from their suit (usually due to poor trim/body position and control of spacial orientation).
In practice the real problem with using a drysuit for buoyancy comes up when divers begin doing more complex dives with double back tanks and stages. The total gas weight might be 30+ lbs and trying to get that much buoyancy out of a drysuit is ridiculous. Only a minority of divers will ever do those complex dives, but why not do it right from the start?