Do you have a reference?

No, but the head of Sony parts confirmed this seven or eight years ago.

Are you sure he wasn't talking about company policy? I have never
heard of such a thing, unless it is during the warranty period. What
kinds of products does this cover?

AFAIK, it's the law. It covers just about everything. Manufacturers are not
allowed to immediately "abandon" discontinued products.

Some years ago Sony told me they would not repair items more than ten years
after their official discontinuance, even if they had the parts. I wouldn't be
surprised if that interval were now down to seven, or even five years.

Sony is like most Japanese companies doing business in the US. They aren't much
interested in long-term customer satisfaction, especially when it comes to
supplying reasonably priced service parts.

If you like, I'll ask the "parts honcha" at Sony exactly what current policy is.