Yes, there is. HGVC was always a deed to points system. Marriott was a week based system that transitioned to a trust fund. For the most part, resale weeks are not eligible to be enrolled into the points system. There are exceptions (bought before 2010, enrolled with a developer purchase), but those weeks exist outside of their club. DRI had unfiltered points access to the collection you bought. Yes, there are heavy restrictions on deeds bought before they transitioned into a trust system, but again, they changed their system from deeds to points. I don’t know enough on Disney, but they always have been a different animal.
HGVC has always been a points system. Even though there are deeds, they have always been associated with points. Since there is a mandatory club enrollment on most deeds, we have to pay to be part of the HGVC system. To take away our use of the system would lead to a lawsuit where there would be 2 potential outcomes; points rights given back or mandatory club membership terminated. One of those would lose HGVC a bunch of money (losing the club fees on any new resale purchase). The other would be paying a bunch of money to go back to what it was with the added bonus of a bunch of negative press.
There already is a precedent set with Vistana. Any of the mandatory deeds were guaranteed access to the system even if bought resale. Even now, after the MVC merger, those deeds still get some access (just the other mandatory Vistana properties) and that situation is only those bought after the systems were merged.
Even the mighty Marriott trust system has a way for resale purchasers to buy points on the market. They pay a hefty fee, but get unlimited access to the system. And it’s still cheaper than buying from the developer. Marriott gets a huge payment and the MF’s keep rolling in.
I will keep saying this until I’m blue in the face, the HGVC resale market is great for corporate HGVC and the individual HOA’s. The have a way to allow owners to divest themselves of their deeds without only work on their part. They get a nice, hefty $1200 or more for every deed someone purchases and if they need more inventory, they can get it cheaply. The HOA’s get their maintenance fees and they can supply HGVC with a nice management fee. Sure they may miss out on some sales, but what’s the percentage of resale owners? Not very high, I would guess.