Last year, they made it very clear that in order to earn the virtual medal, you only needed to walk or run a grant total of 13.1 miles before the end of the virtual period. They explicitly stated that virtual participants did not need to get those 13.1 miles consecutively and that it could be done over days or weeks. There was no requirement to prove that you had finished the miles and they would send the medal. If someone registers for a virtual runDisney event, they'll send the medal regardless of whether or not you did the run(s).
Now, they were also very clear that Kessel Run could only be earned by finishing the Dark Side Half within the usual runDisney pace requirements. Meaning you could walk 1 mile on 13 consecutive days and earn the virtual half, but if you were swept during the Dark Side Half, you would not receive the Kessel Run medal.
Final note. Last year, they shut down Kessel Run registrations before they closed the virtual registrations. So it was possible for someone to register for the virtual half in February and register for the Dark Side Half in March, finish both in accordance with the different rules, and not receive the Kessel Run medal.