If you already KNOW that Trinitron displays are gone, then there's no uncertainty. The Lindy effect is a heuristic for making decisions under uncertainty.
The relevant situation is if you have two things that still exist, and you want to guess which one will last longer. This doesn't override other facts about the domain -- it's SOME information in the absence of any other knowledge. It's for poker players, not scientists.
The example I gave was the new cloud blog startup vs. the old hosting platform. Which one would you put your blog on if you wanted people to read it 5 years from now? All other things being equal, I'd take the old hosting platform. But if you think the startup has a really good business model or you like the founders, maybe you choose that one. It's just common sense.
Another example might be cold-blooded crocodiles vs. a warm-blooded mouse as an example. All things being equal, you could guess that the crocodiles will survive further into the future, since they were here first. But someone with a specific theory or expertise could also argue that the bigger animal is less likely to survive, etc.
Similarly, we already know that dinosaurs are gone. This isn't a situation where you need to act or make a prediction.
Someone who understands Bayesian statistics can probably explain it better than me, but you have to take into account existing knowledge, and update it with new knowledge. Picking out something that you know is obsolete isn't relevant.
This article is a little different -- "things my son would use" implies that they're still popular, not just extant. Both questions are interesting, and influenced by the same principles.
The Lindy effect is one reason I'm working on https://www.oilshell.org/, because shell is now more than 50 year old, much older than Python/JS/Ruby, etc.
Concrete example from the last few days: https://news.ycombinator.com/item?id=26746280
i.e. When people want to explain a modern cloud platform, they use shell. Go would have been more obvious, but shell is clearer. Lindy prediction: shell will outlive Go :)
For example nobody expects the 2004 Toyota Carolla to be forever but the gas powered car will be far harder to kill.
Trinitrons are still to this day the best tech for displaying old games, and people will pay over $100 for even a consumer-grade unit without SCART.
For the professional grade PVM and BVM monitors, people will pay thousands for a large (21"+) one and they sell like hotcakes.