It can definitely be caused by old MIBs/etc.
Sorry, the NOTIF grep was just giving a way to see which MIBs have traps defined in them (not all will) and to help determine what's going on if you aren't seeing the ones you expect so that we can hone in on the actual issue of why you aren't seeing them.
I guess a good question would be what trap do you expect to see but aren't seeing?
I'll get the new ones imported and let you know what I find.
Let's move this into a ticket, I have a process that I use to clean up MIBs but it's complex and I need to test it out again (it's been a while) and it'll be quicker to move to a remote session if needed.
Please create a ticket for this and include a link back to this forum thread:
https://support.nagios.com/tickets/