The published Dungeons &Dragons 5th Edition adventure DDEX3-07 Herald of the Moon awards a magic item called Shadowsong.
In the original adventure, Shadowsong is a very rare modified Oathbow (bold for emphasis mine):
Weapon (longbow), very rare (requires attunement by a ranger)
Each of the elven oathbows are possessed of mythical power and ancient legends. Shadowsong is hewn from a supple length of yew and features curious green metal tendrils snaking through its length. It glows dimly in the presence of humans. The description of this item can be found in the Dungeon Master's Guide.
In Adventurers League play, after the Content Catalog v9 update (p. 28), this bow was changed to a +2 weapon (bold for emphasis mine):
DDEX03-07 Herald of the Moon
This adventure features an item that is no longer acceptable under D&D Adventurers League guidelines, as it deviates from the attunement standards in the DMG. Instead of Shadowsong, this adventure instead unlocks a +2 weapon (longbow or shortbow). This +2 weapon has the sentinel property and glows dimly in the presence of humans.
A +2 weapon is rare, not very rare.
So, taking into account this change, what rarity is Shadowsong?
The content catalog doesn't mention the rarity.
Does this mean that it is unchanged, and still "very rare"?
Or should it be the rarity of a usual +2 weapon, and thus just "rare" instead?