iOS and iPadOS 14 betas seem to have an odd understanding of tabs

I'm running the iOS public betas at the moment and something struck me - both iOS and iPadOS have very odd understandings of what browser tabs are. 

In iOS, we can open a new browser “sheet”, but the menu item says tab:


Yet, in iPadOS, doing the same action says “open in background” even though it literally does open what humans would recognise as a new tab:


I have logged this as an issue with the issue number  FB8508461 — not sure how to make this a link