They won't change to different use years - they stay as is.
Access (CWA) points are like a mutual fund of points...you own a tiny piece of a trust of points, made up of points contracts from many different wyndham resorts.
The advantage is you have fees that are stable-ish and not really affected by special assessments..you also have ARP privileges for all of the resorts where the CWA trust owns contracts. (The ARP is limited by the amount of points that the trust owns, so the ARP privelege for a particular resort isn't quite as good as owning at that particular resort).
I don't own CWA, but if I were buying now, I would strongly consider buying (resale).
If you really want ARP at a particular resort, many times it is better to buy a UDI contract deeded at that particular resort. But, there are cases where CWA will get you ARP at a particular resort for lower maintenance fees than if you actually owned a dedicated contract at that resort.
Not all Wyndham resorts are in CWA. But if you own CWA, you can book all other resorts Club Wyndham at ten months.
CWA maintenace fees are average to maybe a little below average for Wyndham ownerships. So, you can get lower maint fees by shopping specifically for those resorts that are really low.