Why is iPadOS 16 not getting a customizable Lock Screen like iPhone?

Unlike iOS16 for iPhone, released 12th September, iPadOS16 is not due for release until 24th October.  Release dates for iOS for iPhone and iPadOS for iPad have been deliberately staggered by Apple. The final feature-set for iPadOS16 will be unknown prior to official release - however, iOS/iPadOS16.1 is expected to be released at the same time.

iPadOS 15.7 was also released 12th September - incorporating essential security updates.

About the security content of iOS 15.7 and iPadOS 15.7 - Apple Support

More information about the forthcoming iPadOS16 can be found here:

iPadOS 16 Preview - Apple

When iPadOS16 is released, it will be available for these models of iPad:

• iPad Pro (all models)
• iPad Air (3rd generation and later)
• iPad (5th generation and later)
• iPad mini (5th generation and later)

We're just users like yourself. Apple doesn't typically announce why a feature is or is not included. You can give Apple feedback at https://www.apple.com/feedback

Leave unacknowledged feedback for Apple.

Tap the link below.

Feedback - iPad - Apple

I just upgraded to iPadOS 16 and I can confirm it doesn't have the customizable lock screen.

I have no idea why Apple intentionally left it out. I don't see any logical reason to.