Look at how they're struggling with Roscrea and Atmora, which are both cases similar to TR: they are, basically, more of the same (at least that's the approach they chose). Cyrodiil is a massively popular project which gathers almost all of the attention of people who want to get into BS modding, which is why I think that there's a chance that it will get done. Other ones though...? Yeah.
Hey, at least PT for Morrowind has made a very detailed maps (I mean it, it's detailed to individual map cell level) of Summerset Isles
They'll surely use it as some point... Yeah...