AV
We ain't outta here in ten minutes, we won't need no rocket to fly through space
Sure, but then why should I bother even owning a PS5 at that point? In your scenario, I'd be better suited with 2 PS4s. Sony isn't making me feel great about owning a PS5.
Also, it's not a $10 upgrade. It's either you buy the $80 version to get both games to begin with, or if you want to play the PS5 version later you have to buy it outright for $70. If you only buy the PS4 version of the game for $60, your only "upgrade" costs another $70. This shit is literally insane.
You'd still be playing the PS5 version of the game on your PS5, that's why you own it - the non-exclusivity on Horizon was announced before the PS5 launch.
Honestly though, I'm just playing devil's advocate, the version nonsense makes my head spin and I would never pay for an upgrade in anyone's shoes. I would bet they'll add an upgrade path for $10 or whatever but it's kinda nutty they haven't detailed that here. And sadly, this shit will continue while people pay $260 for a version of the game that comes with no disc, but some model that cost maybe $5 to manufacture.