Unfortunately the corresponding video clip has been taken down, but about a year ago someone posting in another thread over in the Trek Art forum made the discovery that the Amar bridge/torpedo room was redressed to be a gas laboratory in the pilot episode of MacGyver (which aired in 1985). They stripped out the more spacey-looking elements and painted the whole thing white, but there was enough of the original set left that an eagle-eyed fan would know what it was. After so many modifications, the set may have been completely unusable to the TVH production crew.
You'd have thought MacGyver could have put it together again afterwards!
That explains a lot actually. Going for a new bridge when the Trek films after TMP love to reuse sets whenever they can always seemed odd. I mean sure, they'd like a set that would be easier to shot seven speaking characters on but I bet they'd have liked a special bridge for the Reliant in II or even being able to build all of the Federation council chamber in this film rather than having to redress the one wall for both sides. There's not that much of the film set on the bridge and you could do the script on the previous set even if it would have been more awkward... so not doing so felt odd.
So of course a TV show wrecked it!