Yes, I essentially paid $10 for the PS5 version when it releases. But it's easily debatable as to whether the upgrade is free though, considering many other game publishers charge an additional upgrade fee for their next gen ports and that is not the case here.
Regardless, I don't think arguing this small point is contributing much to the topic of the thread, which is generally about how much of a shit-show this game has been since launch, esp. on consoles. Apparently next gen ports are not much better still given they had to delay it well over a year after its launch.
The game being free is just marketing. It isn't actually true.