Choosing the channel branch

[wongcc2012]

I am new to this software and have been playing around between Stable, Preview and Nightly. I found that 3 versions are sightly different in the UI and UX. the preview / nightly have much more options. May I know will they migrate to stable release later? (such as choosing RDP version, auto resizing).
Also the menu UI is also different (example is "options" in tools > options) while nightly is in (file > options)