Depends. If you had IDCs pushed into the 90s on the stock pump, with the stock MAF scaling you might not hit rich AFR targets. Since the stock MAF scaling isn't too awful many tuners will not change it, but just target a slightly higher AFR than is wanted.
For example you might target 10.5 AFR knowing very well the stock fuel system can only hit 10.8, which is what you wanted all along. Now you upgrade the pump and suddenly you can reach 10.5 AFR or even richer. You have more safety in that your pump isn't getting its neck wrung, but you will probably lose a bit of power.
While I might not re-tune the car for this I'd probably want to check AFRs at high revs to see they are what you wanted and tweak to suit.
Don't type things you wouldn't dare say to someone's face.
Obligatory 'build thread