reg. fluidity list

can it happen , suppose someone is assigned work til March, working on an assignment on the current day and it's official on my boss's tracking also,... suddenly all of sudden within a day- work is assigned to someone to put me in the fluidity list etc. ? suppose if I had never even asked for promotion, release, hike also.

Is the fluidity list happening only to those who are idle in projects? not to those who are working in projects ?