Sod players will not be going to MoP and classic plus is at least a year away.
I suggest you release a fresh SoD server with todays SoD client that includes all the lessons learned over the last 18 months.
- No leveling phases. 1-60 available at launch.
- No lockouts for BFD, Gnomer or ST. Adjust exp gains to be like other dungeons this way players can spam them for gear or alternative to questing.
- No spammable incursions.
- MC released 2 weeks after launch and then each phase 2 months apart.
- Once life cycle is over, merge players to existing SoD server.
SoD players would be far happier with this over a free boost to a version of the game they have no interest in playing