Starting in OS X El Capitan 10.11, Terminal's font smoothing is reduced for light-on-dark text, so that the overall weight is closer to the weight of dark-on-light text, improving readability by opening up counters (the open spaces inside glyphs like “e”), for example.
You should find that it matches Safari's text rendering for light-on-dark text. It addresses the issue referred to in the question you linked: Is there a way to make the terminal's font less blurry?
This new behavior is automatic and doesn't read the AppleFontSmoothing preference.
If this is important to you, I recommend filing a bug report asking for either Terminal's new behavior to honor the AppleFontSmoothing preference or to add a Terminal-specific preference to control font smoothing.