My biggest worry with the Skyliner was the heat, and that was pretty much unfounded. I'm pretty sure Disney is going to move forward with expanding the Skyliner.
Monorail.... Last new Monorail track was install back in 2004 in Las Vegas as an expansion of the old MGM / Bally's system that used two of Disney's older Mark IV trains. They installed about 4.4 miles of track which is about the length for TTC to Epcot. It cost nearly $650 Million.... ownership of the system has changed hands several times as they keep going bankrupt. Now operated as a non-profit, but it costs to ride it... can get a weekly pass for about $60.
Anyway I don't see Disney wanting to foot the bill for this.... heck they don't even like replacing the existing trains that are now 34 years old and way past the refurbishment that the
Disneyland Monorails got