I think the strobist way of shooting
is new. It's different to anything that has gone on before, and its widespread popularity is really very recent.
I think the strobist style is about using flash in unconventional ways - using flash in situations that would not normally be handled that way, or even handled at all, putting light in unusual places, firing guns through modifiers and gels etc. Usually hot-shoe guns, but not exclusively.
The technology to make this all happen is quite new. TTL-auto flash, wireless remote firing, affordable radio triggers - that's all quite new. And none of this was really practical pre-digital because setting up multiple flashguns in unusual locations, then trying to work out an expsure that is anywhere near accurate - that takes a lot of time and skill with a meter, but only a second or two with digital by firing off a test pic.
The other thing about digital is that you can shoot with decent quality at high ISO - being able to use 400 or 800 ISO instead of 100 ISO with good quality film, increases the effective power of hot-shoe guns massively - like 300% - so they can now be used in ways that were impossible before.
All that is using new technology in new ways, and I think it deserves a new term. I like strobist

Whether or not you also have to be an American new-age hippy with a ponytail is quite another question.