It was confirmed in October by Imagineer Chris Beatty that there will be no M&G in the old Skyway area (New Tangled Bathrooms)
From the October 15, 2012 Live chat on the Disney Parks Blog with Imagineer Chris Beatty...
Jenn Fickley-Baker:
We've also received several questions about construction going on elsewhere in Fantasyland, in the area where the old Skyway attraction was. What can you tell us about this area?
Monday October 15, 2012 2:42 Jenn Fickley-Baker
2:45
Chris Beatty:
Not only have we looked at adding new guests experiences to the New Fantasyland, but we looked at opportunities to enhance guest comfort. Many of you are curious to know will there be a character meet-and-greet in this area, but at this moment there are no plans.
This area is mainly being constucted for two reasons:
1. Open up the walkway/path to allow for greater guest access between Liberty Square and Fantasyland.
This has long been a bottleneck area and with increased guest traffic expected because of New Fantasyland it is really needed at this time.
2. Increased bathroom capacity and relocation.
The bathrooms needed to be increased in size due to the amount of people visiting the area (current Peter Pan bathrooms are too small to accomidate increase guests). Also these bathrooms service Liberty Square as there are no bathrooms in Liberty Square because there were no bathrooms in colonial times. Further there was greater need for more handicapped bathroom space.
Further the bathrooms are being relocated to this area (which has been previous unused for years) to free up the space where the current bathroom is by Peter Pan to expand the queue there. It is rumored to be an interactive queue (like the Pooh ride is currently).
So that all being said, adding a meet and greet to this new bathroom area, especially one as popular as Rapunzel would not be good in this area. It would lead to increased bottlenecks to releave them.
Rapunzel willl probably meet along with other princess in the Princess Fairytale Hall when it opens in 2013.
As far as putting the her tower where the bathrooms are, it is just themeing. Just like the new bathrooms in Storybook Circus are themed very well, they have gone ahead and themed these new bathrooms and allowed for better visuals in the park.
Currently you don't meet Cinderrella at her castle (unless you eat there). Most meet her in Town Hall and in the future probably in Princess Fairytale Hall. Rapunzel no long lives in the tower as she has been freed/escaped from it. So she does not have to meet there.
The theme of the area should be really nice those. Plans I have seen on other sites show that there will be a waterfall and running streams and that there will be the sun emblem from Tangled on the ground in the courtyard area (similar to what Rapunzel painted on the ground in the movie).