Originally Posted by
Brickfire
This ^^^^
Corollary: What was true 6 months ago let alone 6 years ago is no longer true. There is not reliable information about what X choice will likely mean to your life 12 months hence.
But... if you bid 737/A320 and want to move to something bigger you can. If you bid 777 or 787 you're staying there two years.
Not if you bid the next seat over when you are sick of sitting rsv.