Made for TV sequels used to be more of a thing and it is crazy to discover them. My favorite useless sequel is The Sting II, which got a theatrical release.
Oh yes, in the 80’s and 90’s sure. Who could ever forget Splash Too? (Hanks and Hannah not included, sold separately.) Or Beastmaster 3 The Eye of Braxus? But I don’t think it had been done before in the 70’s. Tv series based on a successful movie being a wholly different beast.