Sounds very plausible. One possibility would be failure to go through the T cell checkpoint that allows maturation form IgM to IgG and other things in germinal centres. There seem to be problems like that with other diseases but whatever happens in ME it is not quite the same.
I always said T cell failure causes the B cell malfunction but I have no idea where exactly it goes wrong.
On another matter: the worst flu ever phenomena. When one is carrier of a low virulent strain and get infected with a high virulent strain would that not cause an extreme response?
With the pathogen I suspect low virulent strains can partly protect against the overt disease from the high virulent strain
