Is Apple going to allow a way to turn off the split view on iPad?

Unlike iPadOS14 and earlier versions, multi-tasking (including split and slide-over views) cannot now be disabled in iPadOS15 from settings. Multi-tasking has received a significant overhaul, both simplifying its use and introducing new controls. Whilst the multitasking features cannot be disabled, they don’t have to be used.

Key to accessing and controlling [and/or perhaps not using] multi-tasking is the small “three-dot” button that is found at the top-centre edge of the screen.

More information about using multi-tasking can be found in this support page:

Use multitasking on your iPad - Apple Support

The iPad User Guide is also a rich source of information about using iPad and its many features. The Guide is available both online using a web browser (such as Safari), or as an Apple Books download:

iPad User Guide - Apple Support

https://books.apple.com/book/id1567104892

Apple do invite constructive feedback, comments and feature requests via their product feedback pages. For iPad and iPadOS:

Feedback - iPad - Apple

No one here could possibly answer that. This is a user to user only forum. No one from Apple is here. My best guess would be NO. Split view is a feature people begged Apple to bring for years. For me, it's an absolute requirement. And if someone doesn't like to use Split View, just don't use Split View.

You can certainly provide feedback to Apple via this link though --> Feedback - iPad - Apple