They've done it before, you know. There's a P-Bandai Perfect Strike expansion pack for the original 2004 PG Strike. All it is is the backpacks for the 2020 PG Perfect Strike, so that anyone who bought the 2004 PG kit doesn't have to buy the entire 2020 PG kit to build a Perfect Strike.

Now, if they already bought the 2005 Skygrasper + Aile backpack, it's not Bandai's problem.