Hmm. Everyone has been assuming Great Comet will do a medley, but couldn't they just do a slightly shorter version of "The Abduction," the first five minutes? They might try to do something to include Denee Benton, but the song features the two male nominees, the ensemble, and a whole lot of energetic dancing and fun. It would be a Hamilton type of approach, showcasing the show as the star.
Given the effort being made to recreate, as much as possible, the setting and the inclusion of the extras, it wouldn't make much sense to do all that for a couple minutes of a dance number and then segue into a truncated ballad. And an extra consideration: Like Hamilton, the big star is leaving in a few weeks. A Josh Groban-as-Pierre ballad kind of works against the musical's long-term hopes. The Great Comet producers don't mind using Groban's star power, but they should want the TV viewers' takeaway to be: That show looks and sounds really fun! I want to see that, Groban or no Groban.