Data collection on chronic covid symptoms is vital. If we don't know how many people have long tail covid or how long for or how it is affecting them we have little chance of effectively treating these people. There's likely to be big, ongoing illness burden to handle as well as a high death toll in many nations, including the UK, where shockingly the government has for months failed to report how many people have recovered from covid. And recovery does not equal 'failed to die of'
This is absolutely a major problem in the whole.
Mis-assignment of an individual to those infected or (worse yet) not infected can have major league consequences of failure to understand both the nature of the quantity of those so effected (incidence) and also of the nature of the factors underlying the progression or protective from its progression.
Without a better understanding of the early disease stages, even understanding whether this represents occult persistence of the virus in some reservoir or some after-disease sequella. Anybody who does not believe that viruses can live as an occult presence fails to learn that Herpes Simplex (HSV I) causes cold sores and Varicella causes late Shingles. It is not impossible that SARS-CoV-2 might have such a limited late functioning, though this is certainly a lesser likelihood.