But how can a private owner of the deeded weeks just convert them to whole ownership? Wouldn't it take a vote by the HOA/BOD of the timeshare units to convert another unit and allow it to join the whole ownership HOA?
I suspect you'd have to read the docs on a case by case basis.
I'm pretty confident that if I assembled all 52 deeds for a unit in a westin or Marriott resort they wouldn't let me be a whole owner and opt out of TS related costs.
An owner-controlled board in a complex where there are already whole owners is likely to be much more amenable.