I think they may have stepped up the front and rear de-planing due to the pandemic. In theory they are supposed to be cleaning more thoroughly, so faster deplaning does allow more time for that. I am pretty sure they were cleaning more thoroughly at the start of the pandemic at least (not so sure now) , they might be they switched to front and rear then and then just stuck with it since it is faster (or just inertia not wanting to change procedure again ).
Bottom line is that it I don’t remember it happening before the pandemic , but it happens a lot now