As far as can remember, the scandal happened when Chatman was at LSU. So her actions were inappropriate at that level--not at the pro level. And I disagree with your thought about the status of a WNBA coach vs a college coach. Coaching in the WNBA is more prestigious than almost any college coaching job, with the exception of UConn and...a few years ago when Tenn was at the top. You are coaching the best players in the country in the WNBA.
Pokey was accused while the LSU HC of having a relationship with a former player which made it bad , but not as bad as Summitt's affair looks now.
Chatman settled for $160,000 after demanding $900,000 for being forced to resign.
Also had a 106–19 record during her time as the LSU WBB HC, that gave her an advantage
looking for and getting another chance as a coach .
Summitt doesn't have that type of record and will be lucky if he gets a chance to return to coaching at the pro or college level, also doubt any HS would want to hire him.
Success forgives a lot in sports, lack of success makes it hard to get 2nd chances.