I don't think ME/CFS dysbiosis is different than dysbiosis in people without ME/CFS. As far as what is needed to reverse it..
We'll have to disagree about that. I expect that the species and numbers of an individual's microbiome varies enough that what is good for one isn't necessarily good for another. It seems reasonable to me that one person would do better on a high-carb diet because that alters the population for the specific needs of that person's body. There may be statistical weight against a specific species of carb-loving bacteria; maybe 80% of the population develops an inflammatory reaction to species x, but other people might not have a response to that one, but might have a response to one that prefers a low-carb diet.
As for the difference for ME victims, what applies to 'normal healthy' people doesn't necessarily apply to us. Maybe those of us who do have a bad response to altered microbiome are suffering from a very specific chemical produced by certain bacteria, rather than general 'dysbiosis'. Those people might be normal and healthy with the same microbiome if they didn't have whatever else is involved in ME.
I just don't feel that there's going to be a diet or supplement regime for altering the microbiome that will be the magic treatment for a majority of ME victims. There might be one that helps a small number, and another completely different one that helps a different small group.
I'll wait for the researchers to resolve this argument.