https://www.nejm.org/doi/full/10.1056/NEJMoa2015432
This is a study of the lungs of people who died. Obviously more study is needed, but it's not unreasonable to infer that people who survive COVID-19 would experience symptoms that most flu patients do not.
> there is no evidence COVID is special wrt long term complications.
Since this coronavirus is novel, and COVID-19 is a new disease, of course there are not long-term studies yet. The lack of long-term data does not provide any support for (or against) the idea that its long-term impact is similar to the flu. So we have to look at what we do know so far, which is that it is different from the flu in many ways.