Does deleting Whatsapp backup from Icloud also delete all the data from phone and whatsapp?

Hi DushtDuryodhan,

We'll be glad to get you pointed in the right direction with this. That's something you'd need to reach out to the app developer about to find out how their service works. You can reach out to a developer following the steps here: How to contact an app developer

"Contact the developer of an iOS, iPadOS, or watchOS app

1. Open the App Store on your iPhone or iPad.
2. Search for the app, then tap it. If you can't find it, tap the account button  or your photo at the top of the screen, tap Purchased, tap "Not on this [device]," then tap the app.
3. The app's product page appears. Scroll to the Ratings & Reviews section, then tap App Support. If you don't see App Support, make sure that you're signed in with the correct Apple ID.

"

We hope this helps you out.

Cheers.