I don't know whether the actual shingle has changed, but the sales pitch
has. 10 year longer warranty (attractive to homeowner), fewer nails
required (attractive to installer) - since all of the disasters, they
are probably cranking out shingles as fast as they can. 50 year? The
replacement value goes down with time, used to be on the website. Keep
an eye by your downspouts after it rains and see if you see piles of
granules.