It doesn't look anything like a weak die strike error http://www.error-ref.com/weak_strikesinsufficientrampressure/ https://koinpro.tripod.com/Articles/DieAdjustmentStrikeOrWeakStrikeQ.htm https://www.ngccoin.com/news/article/1115/ A coin that’s spent time in an acidic or caustic environment is going to lose mass. Even assuming your scale is properly calibrated and leveled, a measurement of 2.5 grams isn’t verification that it’s copper plated zinc. The fact that zinc isn’t exposed is a strong indication that it is a copper cent.
I measured the thickness of it. 0.60" Three others I measured were the same or a bit less. I think the bubbling is just a plating issue which was common, especially in the early zinc cents.
I'm sure of the weight as I've measured many copper cents - all right around 3.1 grams and many zinc cents, all about 2.5 grams. Also, the cent is 0.06" which is right at or a tiny bit over the others I measured. If corroded, I would expect some loss of thickness and weight.
High heat could be right. Might that make the bubbling on the surface more intense? Still does not explain the overall weak details though, I think.
What you see on the coin's surface all occurred well after it was already in circulation. It is not an error coin of any kind or type, imo.