Just curious or are they merely window dressing?

not exactly window dressing as it is computed off some idea of what the better team is, but its not like they sim the game and put the avg score or anything remotely close to it. id treat it as window dressing.

window dressing now, but it used to tie into the what if sports book page that no longer exists where HD owners could compete for reward points by betting on games.

It reminds you not to be lazy and forget to gameplan against a sim team when you're a 33 point favorite.  Otherwise you'll get Upset! Happened to me and I'm still not over it! LOL!  I use it to help with gameplanning.  For example if I'm considered an underdog I may play slowdown or if I'm a huge favorite I may play uptempo and set my backups to play more minutes when the game is decided. 

why slowdown when you are a underdog, it seems to limit the number of shots your team gets. it seem to me you would want more shots.

For me it depends on the team I'm playing and the matchups as I don't always play slowdown if I'm the underdog.  There are several factors I'll consider when deciding to go slowdown or uptempo.  If I'm playing a superior team then slowdown would help limit the opposing team's possessions, give my starters more playing time due to less fatigue, and thus give me a puncher's chance if my team is shooting efficiently.  Running uptempo against a superior team could be more disastrous as it causes more possessions leading to an increased likelihood of reaching an average outcome, i.e. superior team winning. 

Disclaimer: I'm not that good of a coach yet so everything I just said could be complete B.S. LOL!