If you do it like some developers, you actually test and modify the code so that Wine is able to run it. Wine is far from perfect and only covers the APIs it needs to cover to get specific applications to work, so it’s not hard to write a program that doesn’t run on Wine.

The only way to block Wine would be to add some kind of DRM, like many other online games do. Wine doesn’t really try to defeat anticheat measures.

In practice, you could easily block Wine by distributing your application in a format that Wine doesn’t even begin to support (UWP applications for example) or by calling a few graphics APIs that are less than five years old.

Edit: looking into it, the only reason the game worked on Steam Deck was because there were certain versions of the client that didn’t include anti cheat. They seem to be enabling anti cheat everywhere now, and that’ll mess with Wine for sure. In theory, Wine can implement all the APIs anti cheat calls and pretend to be Windows, in practice I don’t think anyone from the Wine team is all that interested in this. Valve worked hard to get some anti cheat working, but they don’t have any incentive to make Roblox work.