I didn't really appreciate it when all the North America asters were reclassified, most into the genus Symphyotrichum which I can barely spell let alone pronounce. But that is the nature of science, very little stays the same for long. When I was in graduate school, I never could understand why the old guys insisted on calling plants by obsolete names. Now I do, they're like familiar old friends, but I still think it is worth it to try to remain current.
As far as wildflower.org goes, websites don't fall out of date as fast as books, but they do sometimes fall out of date. Depends on how determined the people running them are to remain current.
