I don't think so, I don't remember there being any noticeable performance difference after buying Aftermath from playing it's base edition on PS5, it seems to already be applied because the hardware can run the game better. When I switched from PS4 to PS5 the performance upgrade was already applied same as any other ps4 game I played on PS5.

GTA, Red Dead, R6 Siege, 2k, WWZ, everything automatically ran & performed better when playing it on Next-Gen. It's like playing them on previous gen the game runs at 70% but when you switch it runs at 110%. There is a noticeable night & day difference. So yeah if you're just looking at performance on next gen in terms of FPS & Resolution performance the Aftermath upgrade isn't technically needed