Notes:

After seeing this pic:
https://knowyourmeme.com/photos/1398107-super-smash-brothers
I decide to make a grid containing the order which the Melee veterans were announced on the official website,rearranged.
Keep in mind that all of the starter characters (except for Zelda) were univeilled at the E3 2001 trailer at May of the same year,the same month the website was first uploaded,so don't think that Fox was the first character announced from Melee altogether,just the first one to get his own page on the site.Also,Peach came before Bowser in the original trailer,but she got her own page after him.
In Ultimate,the unlockable melee newcomers are ordered in VS. matches unlocking criteria from their debut in the series,rather than using the order from the site.