My opinion is that Gaara still has his control over sand. For one thing, unlike Naruto, Gaara was fused with his beast before he was born, and I'll go on a limb and quote fillers here, but didn't Gaara say he wasn't going to rely on the power of Shukaku anymore? I'm thinking that his ability to control sand is unique to him, a side effect of being fused with the bijuu, but just because its gone doesn't mean that it never happened to Gaara, I'm sure some influence/powers of Shukaku still remain in him.