^ Yes, it does; the ratings for seasons that have featured returning players have generally outperformed seasons that haven't ratings-wise, and are generally considered to be among the best seasons of the show from a popularity standpoint.
Heroes & Villains is generally considered the best season, but the others? All Stars was boring and predictable. The first Fans vs Favorites was pretty average. Rob's season was pretty good, I guess. Coach's season was passable, and last season was average. Guatemala, yeah, I would consider that among my favorites but not because of Stephanie and Bobby Jon. (And why haven't they ever brought back any of the great people from that season?! Danni, Rafe, Brian, Amy, the entire cast was gold that year.)
Other than Guatemala none of the seasons where only two or three cast members came back have been that great.
I have to question your statement that the seasons where cast members came back have better ratings, looking at the Wikipedia page.
Yes, All Stars and Heroes vs Villians got higher ratings. South Pacific, One World and Phillipines did not. They seem to just be normal seasons in the gradual decline of ratings. Guatemala got lower ratings than the season before. The first fans vs favorites got lower ratings than the season before and after.
It seems that bringing back old players only generates higher ratings if the entire cast is old players.
If I were to rank the best seasons:
1. Heroes vs Villains
3. Season 1
4. Pearl Islands
7. Russell season 1
9. Season Todd won (Todd & Stephen, why have they never come back?)
10. Rob 4th season (Okay, that was a pretty good season.)
If they were going to bring back somebody who was voted out early, why Francesca? Why not Betsy? Why not 'Beat you down' Amy?