Most TA's could not monitor these options if they have (hopefully for them) a lot of clients. It would be way too time intensive.
Worse, the promos that NCL is constantly putting out there are often jargon changes with no price incentives or changes - wheel spinning to follow those.
Monitoring your own is the best way to catch any better deals.
There were some comments about final payments coming due. That's one where the TA should keep a follow up file - for everyone's benefit.
I'm currently working with a large, online cruise specialist agency. They have automated messaging for every step of the process. As for final payment, they sent multiple reminders. But something was strange - the date given was 10 days before NCL's requirement. So, I called the TA and asked "what's up with that?" I was told that because some clients, despite multiple reminder emails, still messed up paying on time; they added the 10 days to give more flex time against foul-ups. 🙄