It appears that the ATF has entered politics.
While there is no cost to continue and not make any changes to a website, there is surly a cost to change a website and post a message stating that a service has been suspended.
Perhaps someone at the ATF volunteered their time to make the change, or perhaps it was a paid employee trying to make a point for the benefit of others.
If you visit the eForm at the atfonline.gov website it states
Due to the lapse in appropriation of federal funds, the e-Forms system is temporarily suspended until further notice.
We apologize for any inconvenience and thank you in advance for your cooperation and patience.
Please direct questions to the OST Customer Support Help Desk at 1-877-875-3723 or Helpdesk-OSTCS@atf.gov.
Kind of like hiring police to inforce no fishing in a park in the ocean. Can’t the government find better things to waste money on?