In v2026.4, it seems that the Delete button (trash can) is missing on the Grid Add or Master/Detail Add pages if the Delete page is not enabled, or if the user does not have Delete permission to the table/view. It deletes unused blank rows or unneeded rows that have not been added to the database yet, so there is no need for the user to be able to delete from the table or view to use it, and it does not use the delete page.
In v2022, the delete button would always appear on the Grid Add or Master/Detail Add pages as I would expect. Some of those buttons are being removed when we upgrade, on the tables that users should not delete from, but it's always OK to use the Grid Add delete.