Classics and typical entry level/basic paper filters should be seen as what they are: Generally best used for shorter OCIs. Not extended drains.
Remember, not so long ago they were the choice for the dogmatic 3k mile or 3 month oil changes. So, IMO I'd max them at 5 months or 5k miles to be on the safe side. For 'my' vehicle.
If the engine is close to 'brand new'? 10,000 miles on a daily driver, clean engine, and getting that mileage in say 6 months might be fine depending on the app and services seen. The issues with ALL basic filters is when trying to over-generalize or quantify the use of a product not intended for extended use based off of the sorts of experiences that it seemingly to made the 'extended use' just fine for that other person.
Who knows if two different applications that have comparbly the same driving habits, oil type, service conditions seen, engine cleanliness, etc may still have completely different results. YMMV.
When in doubt, stop being cheap and pay $5 more etc for a filter that can do the extended interval in YOUR vehicle. Not sure on the classics, or other basic filters? Cut them open and post.
However, don't expect great results based on others experience. That's setting yourself up for failure. It's like trying to run dino to 10,000 miles constantly based off of someone else's UOA with no further data. Do not over-generalize or make blanket statements. Each oil, filter, etc are just a tool. Use it wisely.
PS: This does not mean a failed filter should be given an excuse, but all reports of failures should be properly recorded and viewed in context before making final conclusions. Just speaking objectively.