Long story short is I got a "new" guitar that has been sitting on the shelf a while. When cleaning the fretboard a TON of stuff came off. Enough that the fretboard is noticeably lighter. Is this something I should be worried about or should have a tech look at?
Yeah really it is at a point.
Letting it stay super dry for too long can lead to splitting and cracking.
Depends on where you live climate and all.
Try to condition fretboard every year at least in super dry climate. maybe 2 or 3x
In a more humid room enviorement every year once would be great.