Owen is really laying all his cards on the table with this one.
The word "doomed" raises the stakes right away, wouldn't you say? It alerts us to the fact that this poem is going into some heavy territory and is ready to face it head on. "Youth" is also very direct, highlighting how the young soldiers are the ones who are doomed and dying, while also suggesting something of the immaturity of the enthusiasm and eagerness to fight.
The weird part is that first word, "Anthem." Merriam Webster Online gives the following definitions for anthem:
Those first two definitions have some religious connotations, huh? That might mean this title is totally ironic. After all, this poem is definitely not a song or hymn of praise and gladness.
But the third definition of "anthem" seems to fit the bill; this poem definitely identifies with a point of view. But rousing? Hardly. Anthem or not, this poem is certainly not causing anyone to leap to their feet and cheer.
So as a title, "Anthem for Doomed Youth" is a bit ambiguous, a bit contradictory. We mean, how can you be glad about someone who's doomed? That means that before we even read the poem, Owen's title is hinting at the contrast between the popular, patriotic perceptions of war, and the terrible doom the soldiers really face. In calling itself an anthem, it's actually questioning the very anthems that are meant to cheer and support our troops. An anthem for a doomed youth is no anthem at all. It's a dirge.