While the article is an interesting read I think the autor left an important factor out in his performance comparation; wing aerodynamics. He talks about power to wight ratio as the only factor in short field capability.
By this, the lear 24 should be a super STOL aircraft.
He mentions the slower cruise speed of the pc-24, this itself can be seen as an indicator that its wing is probably more optimized for lower speed than the faster competition.
And if you take a look at the doble sloted fowler flaps,you see that this wing is meant for high lift at slow airspeeds. Phenom and Lear wings have way simpler high lift devices.
Pilatus also has a completly straight trailing edge for flap effectivness.
So the pc-24 should have quite a bit lower Vref and takeoff speeds, alowing the best field performance numbers in its class.
So, you can not focus on power to wight ratio only, but the autor even takes the Grob SPn as an exemple of good P/W ratio for a short field jet with 0.4, while the ratio of the Pilatus is a very close 0.39!
Yes, the landing gear look quite short, but that is also true for jets like the citation I/II/V wich where also capable of unprepared field operation.
In conclusion,I personaly see no reason to doubt about Pilatus takeoff performance numbers.