Simple answer: no. Ferromagnetic hysteresis increases with temperature, and the hysteresis here is stronger at lower temperatures. The amount of hysteresis they see at low temperatures is also too much to explain with undetected contamination. Plus, the scientists posted a picture of them fully floating a sample upside-down, which is pretty hard to explain away.

Complex answer: Maybe. Copper sulfide does a lot of weird things, and it's very easy to screw with ferromagnetism in unexpected ways. It's totally possible there's a lot of iron in this sample, and the huge incentive for room temperature superconductors is a powerful temptation to slant your data... or fabricate it entirely: https://www.science.org/content/article/plagiarism-allegatio...

That's my alma mater :(