Based on this status page for the IRS FIRE system, I'd say that e-filing of 1099s at this time is not available again until after Jan 8th. Whether using ATX, some other software, or online, don't they all ultimately go through the FIRE system or not? For example, Drake creates a file but I enter my own transmitter number and log in directly to the FIRE system and upload the file. With ATX software it's more seamless, but aren't they acting as the transmitter and still going through FIRE since they aren't going through MeF?
https://www.irs.gov/e-file-providers/filing-information-returns-electronically-fire