The only way for this change to *break* something is if:

1. They're turning warnings into errors, or are otherwise sensitive to a deprecation warning being emitted
2. They're running code programmatically by way of an interactive REPL path

I think we're far more likely to break something else messing about with TTY detection, than we are keeping things as simple as we can and saying that if folks are running code as if they're a human rather than like a computer, then they're going to get the same deprecation warnings we want a human to see. *If* we get significant bug reports about that during the 3.6 alpha/beta cycle, *then* we can potentially consider limiting it to cases with an actual TTY. I just don't want us to borrow trouble and make this unnecessarily hard to test in the process.