does a buyer get a notification when a seller updates their model?

I guess it applies only if new files are uploaded

Yep makes pretty sense Forester. Changing one word from italic to bold... and spamming a buyer with "revised version" would be a big no go.
I guess it applies only if new files are uploaded (fbx, obj etc.).

Perhaps the notification is sent only when the product itself is updated. Not when the product description or images are updated.

Like @LemonadeCG said! From time to time I change something minor on the model, descriptions or something similar and on some old models probably more, like update. It would be good to have a separate update button.

Among other things, a model that I purchased here last year just got updated, and I received the notice that it had been updated. Is good as I just downloaded the revised model.

Yes