I hear you on the out of sight out of mind thing on the littler kids, but, I dont buy it.
I think it is actually just very good denial mechanism in place*.
Mine will vocalize his anxiety in counseling(about daddy). Not to me, AND NEVER to his daddy.
BUt, I saw last week, that his daddy coming over to buy him a bike and acting slightly erratic set him into an anxiety attack. It was really hard. He is 6.
I know. I have similar questions about letting the emotional sleeping dogs lie...
I have been just asking him,. "do you need to tell me about any worries from today?"