Can you can harvested yeast? or would the temperature kill the yeast?
Yeast are living organisms.
You will kill them. That is the whole point of canning - to kill all living things in the jar.
With sound sanatition you can put them in canning jars and just seal them.
Yup, I put my harvested yeast in pint canning jars. I boil the jars first to sanitize them. I use starsan on the lids. Fill them up to the top and put them in the fridge. Nothing further is needed.
There are a terrible lot of lies going around the world, and the worst of it is half of them are true.