Originally Posted by
Brocc15
I was not sure if sometimes years go by without opportunities to bid over to other aircraft at Delta.
Thank you

Yes. Things can definitely stagnate. Even go backwards.
You can absolutely get stuck in a category for long periods.
It has happened in the past and almost certainly will in the future.
Your guess is as good as anyone else's on predicting the US and global economy, war, terrorism, oil prices, etc.