I'm going to decline this suggestion.  Antoine is right that this is a can of worms best less closed.  Likewise, Richard pointed out that there is potential to break existing code.

FWIW, the existence of super() does not imply that all existing classes need to rewritten with super calls.   "Cooperative multiple inheritance" implies a certain degree of pre-planning for meaningful cooperation between the classes.  For generic threading that doesn't seem plausible.

Also note that the referenced super-considered-super article shows how to incorporate non-cooperative classes in the chain without requiring that the original class be modified.