Think the big problem with Bright, as was with McAlinden before, is the complete lack of football when included in the first team 18.
He was getting virtually no time off the bench and was completely removed from U21 squads to fulfil that duty. Given his age you'd imagine he's still got some progression to be made through that level so I don't see any real harm in him dropping back down for the time being, whereas McAlinden was a fair bit older and had nothing to prove with the U21s.
Still seems pointless bringing Holt in though, why not just let Bright play the midweek U21 games and still perform first team bench duty. If he picks up a knock then it shouldn't be any harm short term to only have 2 forwards when only usually playing 1, if it's longer term then you bring a replacement in.