I just came back from the Apple Store and checked out the mini 7 in person - Yes the jelly scroll is still there
Out of curiosity I also checked the iPad Pro M4 11 and 13 inch...I can see the jelly in portrait mode too, and I double checked that promotion is NOT disabled. (But of course everything looks perfect and normal in landscape mode)
I guess Apple's message to anyone who uses an iPad in portrait mode is: "**** you, you are using it wrong"
I can clearly see it on my Mini 6 (though it doesn't bother me) but not in the least on my M4 13".