If by 'dated' we mean by the sound of an album or song we can tell when it was recorded then.....

The 1980s albums - and we're talking sythns here - 'generally speaking' they have a distinctive sound that immediately says 1980s.

The 90s albums less so [generally speaking] because of the live band sound. Tony M had little impact on the sound in terms of number of songs.

I am very surprised how dated D&P and Symbol turned out to sound like. When they came out, hell even years afterwards the general sound was very much up to the current date (sans perhaps the raps, but that's another issue). Now, I can hardly bother listening to them.

It's all relative folks!
Funnily enuff (don't know if it's a word, but I've always used that expression - maybe it's an Aussie thing), I found that PR dated really quickly. It remained a classic, but for me wasn't really listenable from '86 until about 5 years ago. By the late 80s, the same could b said 4 1999. OTOH, I found that DM and Prince, which had sounded a bit dated in the mid- to late 80s, sounded cool in the early 90s.
I think GB was the quickest to date (excluding Rave and NPS which sounded stale from day 1 ), and unlike almost all others, it never really returned for me.
0+> has a kind of dated sound, but holds its own, I think, far better than D&P, but I'm sure both will sound less dated in a few years.
Emancipation - well, most of us didn't really like the overall "sound" anyway, so it's hard to say. (Jam O the Year was never cutting edge in my books!)
Anyway, what I'm trying to say is that what sounds dated has as much to do with what year it happens to be now, as it does with what year the recording was made, and it changes all the time (and that's w/o even considering different tastes).