Yeah my guess is maybe they didn't have "Blizzard Warning" in their particular toolbox until then maybe?
I think Des Moines only recently starting using Red Flag Warnings, or one of the Fire Weather products, that back in the day would have just been mentioned in Wind Advisory text.
Bunch of others have been axed and are defunct. Growing up in addition to winter storm there was
Snow Advisory
Blowing Snow Advisory
Snow and Blowing Snow Advisory (i think)
Freezing Rain Advisory (notch below Ice Storm Warning)
They've all been collapsed into just Winter Weather Advisory now.