Madonna's "Who's That Girl" not on GH?

Madonna has had a few albums where she re-releases material

“You Can Dance,”
“The Immaculate Collection”
“Something To Remember”
“Greatest Hits Volume 2”

I was wondering why “Who’s that Girl,” and “Causing a Commotion” have never appeared on them? They were fairly big hits, reaching Number 1 and Number 2 respectively.

Is there any reason other than Madonna or the record company didn’t want them on albums.

I realize sometimes it’s a matter like the Hall and Oates song “She’s Gone,” is on different lable than the record company releasing the Greatest Hit’s package.

Or like when Michael Bolton released a GH package he left off “Love Is A Wonderful Thing” because the song was involved in a lawsuit where he lost (Some of the song was inadvetantly taken from another song called ), so I could see where the company wouldn’t want to promote it.

But is there any legal reason or conflict of record companies that prevented “Who’s That Girl” or “Causing a Commotion” from being re-relased on a compilation CD?