Most of the studies mentioned in the overview article are small, have not been reproduced and are of no better quality than the usual biomedical research into ME/CFS.
For example, the study on pulmonary abnormalities included only 11 Long COVID patients, the one on myelin loss only 9, the one on small fiber neuropathy 9, the one on blood cloths 11, the one on Invasive Cardiopulmonary Exercise Testing 10.
The longitudinal studies that follow-up on patients from COVID-19 infection to see what factors differentiate those who go on to develop long-term symptoms seem the most interesting but they didn't use long-follow ups or strict definitions. It would be more interesting to see what differentiates those who remain severely disabled more than a year later, rather than people who still reports symptoms after 2 months.