When creating products with Printful, integrations like Etsy require that all selected colors are available in all sizes. So when you push a product to your store with one or more discontinued variants, those variants will be shown in your store as Out of Stock.
You can also unselect all the discontinued variants when creating a product to avoid having Out of Stock products in your storefront. For example, in the screenshot below, you can see the discontinued product colors and sizes. Therefore you can either remove the color from your store or the sizes from all colors.
