It's a good idea if you think it's a good idea. It's a personal decision.The instructor didn’t say it was required, but that he thought it was a good idea and that the police he has spoken with said they prefer to be told up front.
He did not mention, so far as I recall, that some states require it, which is an important omission. I did not know about that.
When I was doing traffic stops, I expected every car to have a gun. Because that's how you handle your safety. Didn't matter if there was a gun or not.
I'm going tell them because more than likely it's going to be in the cup holder of my console.
Trick is, don't get pulled over.