Exposed stringer foam at transom

[Starling]

Hello all,
I'm about to start tearing into my 89' Tracker 20 soon and noticed that the stringers that extend to the transom are open on top exposing the foam . The boat has been sitting for a while and a little rainwater has been collecting so do you think it's a significant issue? I worry that the foam has absorbed it's fill and I need to remove and replace the foam.
Go easy on me as this is my first owned boat and my first attempt at restoring a boat as well. I'm patient and handy with some common sense so I'm hoping this will serve me well - Along with advise from this form