I've addressed this issue in my last post(paragraph 1 & 2).
Again-what is commercially viable for one artist isn't necessarily commercially viable for another.
Karen & Olivia were two totally different types of artists with totally different markets.While they happened to be close friends,they had nothing in common professionally.
We could look at Karen & Olivia's 1978 albums as a case in point-Karen's "Christmas Portrait" and Olivia's "Totally Hot" were as different as night and day.And,both albums were designed for totally different record-buying markets.
We could also look at both of their 1980 TV specials as another case in point: Karen's "Music,Music,Music" and Olivia's "Hollywood Nights" were,again,totally different music presentations that were geared toward totally different TV-viewing audiences.
It seems you didn't read my entire post of which you quoted but picked out what you wanted.....
my quote: "I say all this because the premise is the same"
of course their music and buying markets were different, the premise is that no one told Olivia, stop you can't make something like Grease that will tarnish your good girl appeal with a bad Sandy? Oh my gosh or worse launch a Totally Hot or animal Physical that might abandon your fan base, we don't know how the fans will react that have been following you through the 70's, these things are too daring and we can't gauge the reaction. No, Olivia was free to move as an artist, Karen was free to spend $100K of A&M's money yet when the time had come to finally release her magic....after everything was complete according to Karen...the brakes were placed.