Did you actually read the first article? Because if you did, you'd know that it entirely agrees with the headline of the second one. What it says is that "long covid" may not be objectively different to other post-viral syndromes, but is a lot more common (because so many people have had covid).
This is actually quite true. ANY post-viral syndrome can wreck your life and/or lead to ME/CFS easily. The key difference is that you get post-viral syndromes with a lesser frequency in other common circulating viruses than from Sars-Cov-2. In addition to that people have Covid around 2 times a year on average, which gives them much more of a chance, relatively speaking, to develop said post-viral syndrome than something like the flu, which people get on average once every couple years.
Dr. Lucky Tran 
Hilary
GreySkies