I can't imagine why that shatter wouldn't be as good as the day it was made.
True story. Back in the 70s, weed came with seeds. Lots of seeds. On average, about a third of an ounce was sticks and seeds.
A friend of mine had a farm and I used to save my seeds for him. Of course we never came close to using them all, and I accumulated about a kilo of seeds that I left in a paper bag tucked way in the back of a closet. A few weeks ago, a conversation in IRC inspired me to dig them out and sift them for shake. I recovered 18.1 g of material.
Now this was from the 70s, anywhere from 1977 to 1980. I used to keep seeds from each ounce I bought separate, with a note indicating what the ounce was sold as, how good the stuff was, and the date. (Most of it was supposed to be Oaxacan or Columbian.) The seeds had just been put in baggies and left in the closet. The weed they came from was mostly leaf, not buds, and this was the shake. It looked brownish-green and under my USB microscope I could see that there seemed to be trichomes—not a lot, but some.
Naturally, I tried some in my FlashVAPE.
The flavour was surprisingly strong. It didn't taste the way I remembered; instead, it had a floral perfume taste, quite different and not unpleasant. The interesting thing was that after about 35 years, I still got a nice buzz from it.
I certainly didn't suffer any ill effects.
In other words, the shatter is just fine. Do not fear the shatter. Embrace the shatter. The shatter will get you high.