I've heard some people on other formus claiming that Legendia was just a hoax in the first place, and was never really official, which seems pretty tough to prove/disprove.
The only thing I can say is that
The MagicBox said that Namco had announced it in Japan, and they seem to be pretty good about being on top of things over there.
Here's a
PGC link saying Symphonia sold almost 200k in it's first week, and that Namco hoped to sell a half-million in total.
Here's a
MagicBox link showing Symphonia as being ranked the #31 in all of Japan in the 2003 calendar year, having sold 311,473 units.
Here's another
MagicBox link showing Tales of Destiny 2 as the #8 game in Japan in 2002, having sold 662,699 units.
If we go with
2002 fiscal year numbers, which cut off at the end of March, we cut out three months of time from when the game hadn't launched yet, and add three months of after-Christmas sales. This gives Destiny 2 an extra 171,208 units, giving them the rank of #6, with 833,877 total units sold.
That extra 171k units at the start of 2003 must have been at a discounted price or something, because it seems that it didn't help Destiny 2 crack the top 100 of calendar 2003, which seemed to bottom out with games that sold 130k units.
I haven't found any "fiscal year" numbers to apply to Symphonia yet, although the fiscal year for 2003 did end more than a week ago now.