Not sure I understand your logic. The user uploads any of the supported formats through the Glowforge web interface and somewhere offsite it is converted into a format that is useable. The Glowforge itself doesn’t read any of those formats directly. It’s a very low level device. In the case of Illustrator they have, or intend, to have a plugin strictly for convenience. They may or may not have plugins for other applications for convenience. If not, you upload the supported file manually through the web interface. The Glowforge team is pretty smart and would fully understand that if the user has to manually convert a file before it is uploaded then that’s not a supported file type. I’d question the moon landing before questioning the statement on compatible formats in such a convoluted manner. It is certainly valid to ask if DXF is still a supported format.
And from Dan on Dec 15th:
“but anything that can output as DXF or SVG should be fine”