I'm not so sure.

In earlier text adventures (e.g., Infocom games), some portion of those constraints were due to the authors failing to anticipate legitimate ways that users would try to phrase things and account for them in the game. But that's not nearly such a problem in anything made since the late '90s, especially if you stick to xyzzy award winners.

The more essential reason for that constraint is that it's just good storytelling. The author of a work of IF has an idea they want to explore. That main idea could be narrative (Photopia or Anchorhead), or it could be a gameplay mechanic (Savoir-Faire or Counterfeit Monkey). But in any case, if your goal is to appreciate the creator's vision, those constraints are critical because they telegraph to you, the player, what you should and should not be exploring.

This isn't an idea that's specific to text adventures, either. The creators of the Outer Wilds deliberately made areas flat and boring when there wasn't anything there for the player to do to advance the story, specifically because they didn't want players wasting time on exploration that would ultimately prove to be pointless. This is also why open world games that do go for a more uniformly detailed world also need to hand-hold the player and tell them where they need to go every step of the way. Without that players would tend to get lost, lose their sense of progress, and ultimately end up bored.

I think that, because of this dynamic, using AI to flesh out the unimportant bits of the game would be a cardinal game design sin. Making bloat cheap and easy does not make it good. I just makes more of it.