Explicit end= makes no difference to the behaviour. In fact, a minimal
test suggests that universal newline mode is not enabled on Windows in
Python 3. That's a regression from 2.x. See below.

D:\Data>py -3 -c "print('x')" | od -c
0000000   x  \n
0000002

D:\Data>py -2 -c "print('x')" | od -c
0000000   x  \r  \n
0000003