Recently, I was helping someone find a PIC week. They were working with a telesales rep I know. Apparently, they are being more picky about the resorts and/or weeks they let enroll. It sounds like they want weeks that have higher trading power. Some resorts were taken off the list entirely. The people who already had those enrolled, still have them enrolled. They just stopped accepting new enrollments for that resort. This is coming from just one office. That one office might be playing by different rules, but I don't think so. This is why I always say, talk to a telesales rep first about what qualifies, before bidding or buying anything.
Also, to add to your comment about risk, there is always a risk they will call the resort to check to see if you own it. If they have any reason to believe the owner might not own the week, they will call the resort. It would be best for the owner to have a copy of the deed handy, in case they contest it. If you don't have a deed, they can void the PIC enrollment, but you're still on the hook for the points you bought. So make sure your telesales rep knows upfront you do not own them yet, and just need help determining eligibility before you buy. Wyndham doesn't care if you got the week on eBay, according to a telesales rep. I guess because Wyndham gets the same rental income regardless of if it's retail or resale bought.
Some resorts can take months to transfer into your name, but a deed proves you own it. Deeds usually don't take that long if you have a decent closing company, but timelines can vary by county. Vacation villages are slow as molasses with ownership transfers. I had the deeds long before the transfer process finished.