S
Sunseeker
Guest
By rights, there really shouldn't be a place for those classes in 5e. They were created in 3e as an attempt to level the playing field for martial classes versus spellcasters, and also as a stealth playtest for some of the 4e mechanics. Since WotC should be aiming to get the martial/magic balance right from the outset, and since we've moved on from 4e, neither of those reasons now apply. Everything worthwhile that those classes offered should really be available as options for the more 'classic' martial classes anyway.
I imagine they're probably looking for themes and particulars that were fun and well enjoyed from those classes to incorporate into the basic martial concepts. I could see Swordsage, Crusader, Warblade all as great themes for existing classes that offer slight modifications in order to create different styles without needing wholly new classes.