Since these are mods, they are often "heavy" (larger file sizes than standard PSP games) and may crash.
The persistence of this search term reveals a few truths about the gaming community: wwe 2k16 psp iso work
If you are dead-set on seeing "WWE 2K16" on your PSP screen, you need a mod. Talented modders have taken the SVR 2011 ISO and replaced textures, titantrons, menu music, and character models to mimic 2K16. Since these are mods, they are often "heavy"
How to make it work:
Warning: These mods vary in stability. Some crash during the Royal Rumble. Always back up your original ISO. Warning: These mods vary in stability