I don't think so. Autoflushing output happens in the C runtime library (libc/glibc) or even above that, and the auto flush flag is also a thing of the C runtime library or the interpreter or application above that. It is not part of the O/S information about the file handle, and so it does not survive the exec() system call. You have to enable autoflushing in Python (or any other application you start).
The flag does survive a fork(), like any other simple variable does.
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)