Before an agency can skip full and open competition, someone has to write a J&A explaining why, an urgent need, only one capable source, a follow-on to existing work, and route it for approval. The higher the dollar value, the higher up the approval has to go, sometimes well above the contracting officer. J&As for planned sole-source awards are usually posted publicly before award, which is your window to argue, through a capability statement or a direct question to the contracting officer, that you could have competed for the work too.

In a sentence

"A J&A has been approved to award this requirement on a sole-source basis to the incumbent contractor." The decision not to compete this one is already made and signed, so a fast, specific case for why you could also do the work is more realistic than expecting the notice itself to change anything.