The current App Store requirements for iPad screenshots are:
12.9-inch (iPad Pro (6th generation, 5th generation, 4th generation, 3rd generation)) 2048 x 2732
12.9-inch (iPad Pro (2nd generation)) 2048 x 2732
Since the images sizes are the same, can I upload the same set of images for both? Or does one set have to show the newer iPad without a Home button, and the the other set the older iPad with a Home button?
If your app really does look different due to the changed safe area and the home indicator, then why not do your potential new users a favor and show them accurate screenshots.
As to whether the reviewers would actually notice if you cheat... nobody here can answer that. ;-)
There is indeed a (subtle) difference that an exacting reviewer may notice.
In 2G, drag bar is missing at the bottom.
For instance, those 2 screen shots for the same app:
On 2G
On 5G, there is the drag bar and so text has moved higher
Agreed with both of the above, but I find it hard to square the requirement with the fact that so many apps use a generic/abstract "phone" in their IPhone screenshots. It's not a specific iPhone model, some of them even bear more resemblance to an Android shape. But requiring two sets of screenshots for the iPad that are the same size suggests that's not what Apple wants/requires.
(FWIW, I can't think of an app that looks meaningfully different on those two iPad categories, unlike an iPhone SE vs a 14 Super Pro Mega Max.)