Peter Ljung says that is considered riding on Thursday. There is automatically a 10 day ban when a rider suffers a concussion
but apparently a rider can get a doctors note saying that he/she is fit to ride which would take precedence over the ban
https://www.svt.se/sport/motorsport/veckan-efter-tuffa-kraschen-ljung-kan-kora-redan-pa-torsdag
IMO even consider riding less then 2 weeks shows that he hit his head way harder then we thought and that he is not fit to rider.
If you suffer a concussion you take a few weeks off to rest your head, not go risking a new concussion so soon after.
There is many athletes in sports that have had to retire due to concussions.