Yes, if Mikkelsen would use the WRC car to test the Pirelli tyres, that would use their allowed testing days. And conversely, the R5 testing isn't limited (except for a couple of weeks in the country where the next event is run in)
Anyway, would you consider possible that Pirelli would supply the tyres for Hyundai WRC team in 2020? The control tyre rule is coming in 2021, maybe they want to compete with Michelin for that role?
Or is this testing for an effort to take part in the WRC2 championship, to be maybe sponsored by Pirelli?