I confess that my favorite production of Chess to date is the original London one (with the 2003 Actor's Fund concert running a very close second and featuring what I think are the best revisions to date), but I think that to accept that Chess is stuck in the '80s is essentially to accept that it's dead. And I'm just not ready to let go.

The thing that's so paradoxical about the show is that underneath all of the synthesized stuff, there's a really beautiful, fairly classical score hiding. I don't think that it could ever play in all its '80s glory in a major revival, because it doesn't (shouldn't!) have that cutesy '80s vibe that audiences love. Those orchestrations were fantastic for the time, but some of the newer ones seem more appropriate for modern audiences.
Company is an interesting case, because the show itself is inextricably tied to the '70s on textual and, arguably, contextual levels... so sounding '70s is appropriate. On the other hand, I completely love what John Doyle has done with the current revival by not-exactly-updating it, but removing it from any period and making it more of a psychological study and less of a piece of societal commentary. I wouldn't argue that that's the
best interpretation of the material, but on a personal level it's the one I've found the most affecting of any of the productions I've seen. I agree that trying to make Company "modern" as in set in the '00s and with orchestrations that reflect current musical trends would be a major misstep, but I don't think the revival orchestrations are reflective of a specific period so much as a chamber orchestra sort of style. I can see where you'd disagree and think that losing the '70s sound interferes with the interpretation of the show, which it obviously does, but in this particular case it opens up a different perspective. So I don't think that the creators are mistaken in allowing different takes on their material, necessarily.