Although the unofficial report mentioned a positive test result for Henry Cavill, Netflix did not confirm these assumptions, but only said that, indeed, there was a problem with the COVID-19 virus, and production will resume as soon as it is safe.
According to Redanian Intelligence, several cast members are back on set already, including Mecia Simson (Francesca) and Cassie Clare (Philippa Eilhart) (as can be deduced from their Instagram feeds), so it is possible that the crisis has been averted and The Witcher will start at full speed again. However, it is not known what about Cavill.
Season three does not have an official release date yet.