It’s the opinion of Rabeinu Tam who lived 7-800 before satmar became a thing...
The reason why you associate it with Satmar is because many Rabonim in Hungary followed his opinion
Not quite exact, Many Hungarian "yekke" kehilos like Pupa, Vien and others keep an earlier Zman than 72 (dependent on Oifek), I believe the Satmar Ruv z"l took it from Sanz and Siget and worked hard to set the Rabeinu Taam Zman as a standard in many places for Motze Shabbos and other D'oreisas.