If it's classical or jazz, the remastered disc is unlikely to be compressed.
If it's anything else, it's unlikely not to be compressed due to unscrupulous producers, unprincipled recording engineers, undiscriminating audiences and supine "artists" who make the loudness war continue.
Albums being remastered to CD are most often given a heavily compressed mastering. It's the very unpleasant result of the loudness wars that have been waging since about 1997. While such treatment does sound better on the crappiest of speakers and iPod headphones, it destroys all sense of depth on better ones.
As far as I know, most SACDs are not given such treatment. They're mastered for better quality equipment.
Because most albums on SACD are mastered differently from the CD version, direct comparisons between SACD and CD are difficult. A listener could easily mistake the improved dynamics on the SACD version as the result of the format.
Strangely, I'd expect any improvements currently audible by SACD over CD to diminish over time. As analog to digital conversion continues to improve, the benefits of 96 khz recording will decrease.
If the recording is a rock or pop album, I often do look for CDs mastered in the mid 90s or earlier. Unfortunately, A to D conversion wasn't as good then.
Classical is another matter. I've never heard an over compressed classical CD. I'm sure they're out there somewhere though.
I too wonder if the CD layer of SACDs is given a different mastering. It would probably be in Sony's interest to do so. If both were mastered the same, listeners might realize how little improvement there is over CD.