Hi! Here's a yet another case this obsolete requirement causes problems: #845464 which is a severity:critical issue (somehow filed as "only" serious) -- an unrelated outdated package causes debootstrap to fail.
This is nastier than the usual cases, such as leaving a bazillion of gcc-$ANCIENT-base at priority:important. And there's no reason for breaking installation just because of an otherwise well-executed, trivial private transition. Thus, this policy requirement needs to die. And to actually fix the issues, instead of merely dropping the mention and thus making the dependencies last forever because of inertia, I urge you to go all the way from "priority of rdepends MUST be raised" all the way to "priority of rdepends MUST NOT be raised, every package is to be evaluated only based on what it directly brings to the user (elevation possibly _moved_ to a metapackage/etc but never copied the other way)" (maybe just a SHOULD NOT for a transitional period). Would you want me to a provide a suggested wording? Meow! -- The bill declaring Jesus as the King of Poland fails to specify whether the addition is at the top or end of the list of kings. What should the historians do?