It seems that old britney changed behaviour regarding versioned dependencies on virtual packages; modified TODO and BUGS.

BUGS

@@ -1,3 +1,4 @@
 # list of bugs for old britney
 #  * if there are no tpu approvals, then all the packages are approved
 #  * while building the upgrade excuses, dependencies on virtual packages can be versioned, but not on UpgradeRun
+#  * if a binary package is found in testing-proposed-updates, but its sources doesn't exist, it is considered and requires approval from RM

TODO

@@ -1,4 +1,2 @@
 # Unsatisfable dependencies are not valid candidates, please drop them from upgrade_me (waiting reply from aba)
-
-# Add support for old libraries (introducing a new operation: remove single binary)
 # Add support for udeb

britney.py

@@ -900,7 +900,7 @@ class Britney:
         # local copies for better performances
         parse_depends = apt_pkg.ParseDepends
         get_dependency_solvers = self.get_dependency_solvers
-        strict = not self.options.compatible
+        strict = True # not self.options.compatible
 
         # analyze the dependency fields (if present)
         for type in ('Pre-Depends', 'Depends'):