I expect burning of fossil fuels will be banned. Spewing toxins into air we all breath is not a right.
As alternatives become available, ICE will largely be banned in more and more areas. I read the French ban on ICE vehicles in Paris that will be going into effect in a couple of years has an exception for restored classic cars.
There is a huge difference between even as many as 100,000 ICE restored classic weekend cars in the world and the 1 billion ICE on the road today. For one thing very few of them will be driven except for special occasions because people will realize EVs are so much cheaper, but enthusiasts will keep them running and restored as hobby cars. They also won't be drivable long distances because the fuel for them will be hard to find.
The total emissions from these cars will be down in the noise compared to other emissions. Look back 110-115 years or so when the ICE to horse ratio was close to the EV to ICE ratio today. Horses were seen as the big pollution problems. The manure collected off the streets of big cities was becoming a staggering problem. The term "tail pipe emissions" originated as a euphemism for horse waste.
My father was born in 1920 and he clearly remembers cars being pitched as the pollution free alternative to horses. It wasn't until we got large number of ICE that we realized that the gasses emitted from car tailpipes wasn't good either.