I've had a two copies of PC CCleaner Professional since 2013 on computers that I still use. I can guarantee you it was sold as lifetime purchase. I know its "pics or it didn't happen"... My receipt at the time shows just "Professional" which makes me think they've been planning this for a while. Maybe build up their infrastructure with honest clients and then flip it on its head after 5 years.
Not a lawyer but here's gobbledygook from my purchase at the time which is non-specific all get out.
I look forward to my pittance in the class action lawsuit in 5-10 years...
Information on Payment, Delivery and Performance.pdf