It will never happen.
There are over 480 million people registered to Skype.
The courts would never pull the plug on that many people in the World.
Sounds like the two programmers have gone a little goofy, they got their money and now want to start a law suit to get "paid-off". A new form of blackmail.
My heart bleeds for them!
They must really be suffering emotionally over how their software is being abused.
Their lawyer did a good job of putting that time bomb in the contract.
Software tends to need changes over time as technology advances.
Hmmm, I programmed for over 30 years, who can I sue over my emotional stress?
SantiagoDR