Neil Wood's young Reds were in second spot behind West Ham United, three points behind with a game in hand, and nine points in front of third-placed West Brom, when the season was curtailed due to the coronavirus pandemic.
The Premier League have decided to finalise the tables on a points-per-game basis, meaning United go up in second place with the Hammers, without the need for the play-offs.
The promotion ensures next term's group will have a competitive games programme, with the club also set to embark on the UEFA Youth League campaign for the Under-19s.
Most of the team in 2019/20 were younger and in and around the Under-19 age group, in any case, with some of the elder members of the squad allowed to go on loan to further their education.