Support wrote:You can add the field "Published" in the feed file and set "False" or "0" for this field.
You will import new products and import this field "Published" with "false". All products will be unpublished.
Yes, that’s exactly what I did right away. It’s just that if the import is automatic, it’s not just inconvenient. It would be great to manually set the field value before importing by default. Price lists do not always have the required fields, and editing them before importing makes it impossible to do this automatically.