To be clear, are you asking about the warranty of the OEM vehicle, or the warranty of the lube maker? Because the approach for each will be similar, but there will be some unique considerations for each. Plus, it depends upon the method of failure, too. Lube related failures are typically chronic, whereas component failures are acute.
Unless you have a much more specific question in mind, it's almost limitless as to the "what if ..." scenarios we'd get into here.
Typically written records (such as the additive notes in your owner's manual maintenance log) are often sufficient enough to show "maintenance" has occurred. And I'd think that as long as you have some recent records (perhaps dating back 2 years) of oil purchases, that would be enough to satisfy the warranty entity. That is, admittedly, supposition on my part. But I find it nearly unfathomable to think that you'd have to produce the oil receipts all the way from mile 1, especially on a high mileage unit that's no longer covered by the OEM and only the lube maker.
Which does bring into light an sub-level topic ... how does any particular company address that of other company products? If you used a slew of different lube brands for the first 100k miles, and you have a lube related issue at 120k miles, is the current lube maker going to blame the former lube makers? If your engine calls for SM or better, and you've used SM or better for it's entire lifecycle, then how does Mobil look upon the issue if they were in the crankcase at mile 120k at failure, if you used SOPUS, Valvoline, etc in a "mix" of choices during the first 100k miles?
Honestly, I think we all worry about this WAY too much. RARE (exceedingly rare) is the concern that a lube will actually CAUSE a failure.