即使销售线索表格已被分配到进行中的推广活动，也可编辑该表格中的所有字段。

This statement is incorrect. While you can edit some aspects of a Lead Gen Form after it's been associated with an active campaign, you cannot edit all fields. Specifically, you cannot change the form's language or the questions asked in the form once it's live. This is because changing these core elements would alter the data being collected and could invalidate the campaign's original targeting and objectives. You can, however, edit fields like the form's name, privacy policy URL, and confirmation message.