Pronounced shift

Hearing the word “debut” pronounced correctly on the
radio today (as dayboo), I was reminded of how in my
childhood 50 years ago it was often pronounced debo, no
doubt by analogy with the French word beau. That version
seems to have gone ouest, but lonjeray for "lingerie" has
proved more stubborn, probably because the degree of
Gallic nasality required to get the lin part right is too much
for Kiwi tongues. Shifts in pronunciation, even within
English, are generally immune to complete and final
explanation, though the mass media are obviously very
influential. You might think Americans have always said
rowt for "route," as opposed to our root, but Nat King Cole
sings root in his 1940s recording of “Route 66,” so clearly
something has shifted in the past 60 years. Rowt seems
certain to take over in New Zealand eventually; already,
when talking about computer connexions, no one would
dare say rooter and not rowter for "router." Other
Americanisms are steadily encroaching on "English"
English: I heard "status" pronounced with a short a on a
Radio New Zealand news item a few weeks ago, and
"process" with a short o on Outrageous Fortune.