I have never once heard of any such thing at ANY time in my own 27+ years of timeshare ownership and experience, but these are a few of the concerns / questions I would have, right off the bat:
1. Why would ANY entity, commercial or private, want to take ownership of a timeshare which the current owner can't sell, thereby willingly taking on inheritance of the annual maintenance fee obligation? That just makes no sense at all to me, personally.
2. Assuming for just a moment it's actually a legitimate proposal (...which I very seriously doubt, quite frankly), how would you ascertain whether this "land" actually has any value, present or future? Personally, I'd be concerned that someone is trying to somehow "unload" their ownership of utterly worthless land. Maybe there is no legal access to the land. Maybe no future building (or ANY other use) is allowed by some undisclosed covenant. Worse still, maybe it's land on which some sleazy contractor illegally buried hazardous waste, construction debris --- or Jimmy Hoffa...
I understand and empathize that you have a timeshare that you don't want and apparently can't sell (...or even give away maybe), but I'd still be very, very suspicious about this alleged "land for timeshare" scheme. It just doesn't add up --- not logically, not financially, not conceptually.
My advice is to not let your desire to rid yourself of this unwanted timeshare cloud (or override) your decision making and judgement...
KC