Ok. This is going to be a different opinion than what I've see thus far...but here I go.
I'm reading this specific part: Please be aware that should you continue to use the discontinued version(s), you may be at risk of potential claims of infringement by third parties
To me, that means that Adobe has structured their specific agreements with 3rd parties (filters, effects, 3rd party processing, etc) such that when a version of CC is no longer supported, the licensing agreement has been nullified. I don't think Adobe would sue anyone for using an older version, they are notifying you as the user that you are no longer protected by such agreements and open to litigation with a 3rd party company. This was probably a power move by Adobe to lower licensing costs for 3rd party tools that they utilize.
I'm a Software Engineer, so take my opinion with a grain of salt.
