Possibly, but:

Before the yeast can start feasting, the PET plastics are subjected to a process called oxidative hydrothermal dissolution to break them down into smaller bits that the microbes can digest.

"Oxidative hydrothermal dissolution" - basically they boil the plastic and oxidize it, I think at the same time. Maybe hydrogen peroxide + water? Essentially this is kind of an accelerated aging.

Anyway, the yeast can't eat the plastic without some processing first, which is probably good because it means existing plastic packages won't just start falling apart. On the other hand if this does get loose, it might be able to eat any PET litter that has started breaking down in the environment due to exposure to sun, rain, ocean water, etc. The absolute easiest waste for this to eat would be any PET that has broken down into microplastic particles and ended up in soil or water, which would be kind of an ideal situation.