The thing I find interesting is that the missing blog posts seem to suggest we're getting a newcomer and an echo.
and if what JaidynReiman is saying turns out to be true we're probably not getting a dedicated Sakurai segment. (that could also be what the "don't get your hopes up" thing going around means) I think it makes a certain amount of sense, the last two Smash reveals have had a lot of info on the game so I'd expect this month to be a kind of a "lull" in comparison. We're likely not getting anything beyond a character reveal trailer.
(Though on the other hand the direct is 35 minutes long, it's not that hard to imagine 10 minutes of that being dedicated to Smash, especially if most of the direct is quickfire style reveals)
and if we don't get a Sakurai segment then whatever newcomer and echo we do get will probably both appear in the same trailer. Unless they randomly decide to reveal an echo in the middle of the direct.
In which case it's hard to think of another pair as fitting as Isaac and Felix. (who would also only need one memory between them since they originate in the same game)
Sora and Roxas are the only others that come to mind.
Edit: I guess there's also Phoenix Wright and Edgeworth but that ain't happening.