The term plastic is so vague and overloaded now that it won't. Is an elastomer a plastic? Depends on who you ask. Does a plastic have to be derived from petroleum? Depends on who you ask.
Plastic, in the industrial/commercial products context, was always a very broad term. In addition to being a broad technical term in industry, it quickly became a moniker for the mid-century industrial chemicals revolution similar to the way "computers" was for the 80s, "the internet" was for the 90s/2000s, "social media" for the 2010s, or "AI" for the 2020s.
tire dust is specifaly toxic to juvinile fish, and as all roads are ditched, any extream early spring
rain event will gather and float a concentrated pulse of tire dust into the equatic environment and cause mass mortality in stream and river bound juvinele fish such as salmon
my understanding is that it is additives used to make tires tougher that is the main culprit, so the anouncement of an essentialy zero cost way to gain longer lasting tires that produce less, less toxic dust is good news