Considering that postgres only supports windows versions that have the new API, it would be good to make the replace.
That is not actually the case. If you check the _WIN32_WINNT logic in src/include/port/win32.h you can see that depending on your building tools you can get a version lower than that, for example if using MinGW.
* memory leak fix to src/common/exec.c * CryptGenRandom change by BCryptGenRandom to src/port/pg_strong_random.c * link bcrypt.lib to src/tools/msvc/Mkvcbuild.pm
If you want to address 2 unrelated issues, it makes little sense to use a single thread and 3 patches.