OK, that will take a bit more time. Lets start with https://www.openstreetmap.org/way/27597535/history or https://map.atownsend.org.uk/maps/osm-deep-history/#/way/41189769

problem is not with whether it is secondary or primary but because change was motivated by official road classification

while road classes in official classification (either of them) do not match to OSM one, this is documented at https://wiki.openstreetmap.org/wiki/Pl:Key:highway#Warto%C5%9Bci and https://wiki.openstreetmap.org/wiki/Pl:Drogi#Klasyfikacja_dr%C3%B3g

this is also listed at https://wiki.openstreetmap.org/wiki/International_highway_classification_equivalence#Examples_of_cases_contradicting_simple_rules

disclaimer: I authored that

mandatory discussion of changes to high road classes is described and documented for example at https://wiki.openstreetmap.org/wiki/Pl:Znakowanie_dr%C3%B3g_w_Polsce#Drogi_samochodowe

A tiny bit ironically added by Pavv in https://wiki.openstreetmap.org/w/index.php?title=Pl:Znakowanie_dr%C3%B3g_w_Polsce&diff=prev&oldid=2919811 very recently there but this is in general supported and was documented somewhere else already (cannot find it right now)

--------------------

would this be considered sufficient?