SWF is flash. Vector graphics are just a subset of the format. Any tool claiming to support that format would have to support the rest of the spec, which is overkill for many vector applications.
Even though Adobe owns SWF, they don't support it in Illustrator outside of exporting.
You can always pull a marketing stunt like .webm vs. Matroska if you want to advertise support for a variant of Flash constrained to just the vector parts.
Plenty of existing tools only support a subset of SWF, mainly the vector graphics and animation parts. It's used for UIs in games and various other applications.
Even though Adobe owns SWF, they don't support it in Illustrator outside of exporting.