Also I think "vegan" is a bad tag to add, even if it was done by the journo. I don't want to open that can of soy worm-substitute, but the point of this doesn't seem to be avoiding the use of spiders or anything like that, rather it's just an efficient way to grow a cool material that bears similarities to spider silk.
I'm inclined to lean towards reconfigurations of simple materials (cellulose in this case) rather than high tech solutions, for the sake of simple and scalable production and lower likelihood of simply laundering the ecological impact from the finished product to the manufacturing process.
That's just a rough heuristic though, I don't know whether this or cellulose-based plastic replacements would be definitively better.
This is just a reconfiguration of soy protein isolate. They dispersed it in an acetic acid solution, applied heat and used an ultrasonic homogenizer, then used glycerol as a plasticizer and dried it out. I was expecting something more exotic, but this doesn't seem difficult to scale.
Edit: Looks like your tea brand is actually plastic free.
That said, they don't use anything exotic. It's just soy protein, acetic acid, water and glycerol. It would be interesting to see how long it would last in a compost pile, but I wouldn't be surprised if it broke down fairly rapidly.