Here is how I understand it:
1. MB and FP+ are both part of MyMagic+, a next gen initiative from Disney but ARE NOT the same.
2. MB is an active Radio Frequency ID (RFID) media that allows people to swipe to charge, gain access to rooms, access FP+ entrances.
3. Swan and Dolphin guests are NOT receiving Magic Bands.
4. Swan and Dolphin guests will likely access FP+ kiosks IN THE PARKS ONLY by using RFID cards tied to their park tickets. S&D does not current have, or is planning to have, RFID enabled room access.
5. Currently, FP+ access is only through MB's, through either current, or previous, onsite stays. For example, some offsite guests with a split stay can have FP+ access throughout their entire
MDE linked ticket if they have at least part of their stay onsite.
6. It is assumed that offsite/Swan and Dolphin/Shades of Green/AP guests will be able to access FP+ in the future through RFID tickets linked to the MDE website. It is possible that MB's will be offered to these guests at a fee.
Bottom line, MB is currently a requirement for FP+ but will likely NOT be in the future.