It does not seem to be applied to any concrete person, but is a rhetorical question inviting, or rather, commanding all faithful to be such servants.
If so, then not only apostles, the distributors and dispensers, "right apportioners" (2 Timothy 2:15) of the word of truth come under this category, but all Christians.
If so, then also those Christians who do not have the special apostolic appointment are obliged to "feed servants", that is to say, grow and nurture those features in their lives, that will not wither with their perishable bodies, that will not be ever taken by the perfidious thieves - i.e. the days and years - but will last forever.
It is, thus, a call to Christians for embellishing their characters, their "inner man" or "hidden person of the heart, with the imperishable quality of a gentle and quiet spirit" (1 Peter 3:4), bearing all gifts of the Spirit of which Paul speaks - love, joy, forbearance, kindness, goodness, faithfulness, gentleness, self-control (Gal. 5:22-23) - that is to say, endless cultivation of those qualities in one's soul through feeding those aspects in our created souls (metaphorically called "servants" because of the feature of createdness) through nourishment of the uncreated Spirit that eternally proceeds from the Father (John 15:26) and divinizes our souls, making us free from Law (Gal.5:23) and from gravity of sin (2 Cor. 3:17), turning us from servants to sons of God (Rom. 8:15), and thus, kings and co-heirs of His only-begotten Son.
Unless we do so, when Jesus comes, we will not be able even to notice and recognize Him, for only through interactions with the Holy Spirit whom He has given us (John 20:22), in Whom we should bath constantly our conscience (Rom. 9:1), we can understand His divinity and worship Him as Lord (1 Cor. 12:3).
And from such people, who will not cultivate in this way the spiritual gifts, and will not make use of the Spirit given to them for this very cultivation, Jesus will not let into His and His Father's and Holy Spirit's kingdom, but "cut him in two" (Luke 12:46), that is to say, remove the salvific presence of the Holy Spirit from such a man, which was his better and glorious part, and which Paul prefers to die than to be deprived of (1 Cor.9:15), and "hell" is nothing else but privation of Holy Spirit.
That's why the Psalmist beseeches Lord "do not take Your Holy Spirit from me" (Psalm 51:11).