A-Pillar rust behind weather stripping - normal?

[ItWillBeSlow]

I recently removed the side and upper weather stripping on my truck and found a nice surprise on both sides. On the vertical A-pillar section, I have some notable rust, see pictures below. This is fairly symmetrical on both sides.

It was not rusted through, however I did make a pinhole with a screwdriver trying to see how solid it was. I have done floor pans/rockers/cab corners on this truck already and should be able to get this taken care of, it was just an unpleasant surprise. I would consider the condition of my cab average for the southeast region.

I am curious if rust is common in this area, and if there may possibly mean anything more. My drip rail area has some visible surface rust, but appears to be pretty solid best I can tell. I haven't removed the windshield or taken the multiple paint layers off yet to know the full condition.

Any tips? This area doesn't look too fun since its so close to the dash.