When updating a model via the workshop editor, the game processes the title and description of the workshop item, and changes them to the processed version upon upload. This can result in unintended changes to the workshop upload’s title and description, as the in-game title/description box doesn’t support certain characters in the title (changing them to ???) and has a cap on the length of the description.
I’m not sure how exactly things work on Steam’s end, so I’m not sure if this is possible, but it would be nice if you could just update the model without updating the title/description.