If Big Sur Suite is not available for points, you can't use an upgrade cert. So I've never used one at Ventana. Nevertheless about half the time I have been upgraded. Never to Vista but once to Coast House.
In my opinion, a nicer room makes almost no difference in how much you enjoy your stay, except that a non-fireplace room would remove a nearly essential part of the experience.
I don't think a standard suite has to be available with
points, that room type just has to be available to be booked.
Sometimes it would mean the same thing, sometimes not. That's how I understand it, at least.