I know of the project, I actually beat OoT for the first time this year with SoH. I didn't know it was just a decompilation, though. I thought it was a reimplementation. Cool.
Discussion
Reimplementing something like this wouldn’t really be possible without missing stuff. it would be very obviously different.
they start with a decompilation. It still uses an emulation of the n64 graphics stack underneath (libultraship).
Its not a complete bit for bit recreation like https://github.com/zeldaret/oot, but it forked from that
There are projects like that, though. Like OpenRA that reimplements Red Alert, Dune2k, etc. Apparently they are obviously different if you played the original enough, but it's close enough.