We do have knowledge about long-term effects from other coronaviruses (SARS-CoV-1 and MERS).
Despite its name, SARS-CoV-2 is not strictly a "respiratory virus". While it is spread airborne, it attacks multiple tissues besides the respiratory system, and causes multi-system dysfunction (including but not limited to MIS-C, type 1 diabetes, celiac disease, acute kidney injury, erectile dysfunction, ...). Many of the damages are immune-mediated, which is in line with what we know about T1D and celiac as autoimmune disorders.
Despite its name, SARS-CoV-2 is not strictly a "respiratory virus". While it is spread airborne, it attacks multiple tissues besides the respiratory system, and causes multi-system dysfunction (including but not limited to MIS-C, type 1 diabetes, celiac disease, acute kidney injury, erectile dysfunction, ...). Many of the damages are immune-mediated, which is in line with what we know about T1D and celiac as autoimmune disorders.