No, this decision does not invent new law (though courts do in fact make law, and it is seen as appropriate for them to do so, both under common law and since Marbury, so inventing new law, had they done so, wouldn't necessarily be innovating). The decision specifically cites the parts of Wisconsin code that apply to rulemaking and why Emergency Order 28 is a rule and not an order. Simply quoting from one part of the Wisconsin code ignoring the other parts that apparently apply (certainly, according to the Wisc. S.C.), is not enough to win an argument.

They found a tortured justification for the result they wanted.

I don't think it's tortured. I think it's a reasonable reading of Wisconsin statutes. Maybe you're torturing your reading of the decision. Or maybe I'm a shill. Any readers that stumble onto this sub-thread will just have to figure it out for themselves, and I suggest they read the opinion because it speaks for itself.

They should also read Judge Dallet's dissent which makes the same points I've been making.

Admittedly I've not read it -- I assume it's reasonable, as I find the majority opinion to be. That's the thing with these court decisions: often you can justify either outcome in reasonable ways. There's no need to vilify anyone here -- it's truly distasteful what's been on display regarding this decision.