Earlier quoted context omitted.
It's happened again and again with other words. "often" (older pronunciation: "offen"), "Anthony" (older pronunciation: "Antony") and "tortoise" (older pronunciation: "tortuss") are examples where the spelling pronunciation still hasn't totally won out. Words where the spelling pronunciation has reached fixation include "falcon" (older pronunciation: "fawken"), "reptile" (older pronunciation: "reptil"), "sphere" (old…
I was with you until tortoise. US English speaker here, but I have literally never heard anyone say “tor-toys”. I think I’d have a serious moment if I did. Is there some link you can throw our way to demonstrate the point? YouTube?
For what it's worth the Oxford English Dictionary lists /ˈtɔːtɔɪs/ ("TAW-toice") and /'tɔːtɔɪz/ ("TAW-toiz") as alternate pronunciations in British English. This appears to be the result of a revision made to the entry sometime after 1989. (The public-facing revision history is not very precise.)