Hi Tealcomp,
You certainly did well and that’s significantly longer (probably double) than the typical life of a mattress that most people would buy from a major manufacturer in today’s market.
They would probably tell you if you asked them but I never have. Most warranties aren’t nearly as important as the quality and durability of the materials in a mattress anyway because they only cover defects in the material and if a mattress has a defect it will usually show up in the first year or two after a purchase (see post #174 here about mattress warranties).
Having said that … their warranty is very unusual because it’s also combined or integrated with a comfort guarantee (which they call their goldilocks guarantee) where you can exchange layers at a subsidized and reduced cost for 20 years (also prorated) so it serves a dual purpose.
You can see their old warranty here and their old 90 day exchange policy is here.
Of course they will be able to tell you more about the reasoning behind the change when you talk with them since they are very open and transparent.
Phoenix