The new graph editor in Maya 2017 has an option in the "Select" menu for selecting anim curves that is off by default.
Current Behaviour:
If you turn it on and then close the Graph Editor (or Maya) then the next time you open the Graph Editor it will be off again. Saving your preferences while the setting is on has no effect on this.
I have tried to work around this by adding
evalDeferred("selectType -animCurve true");to my userSetup.mel so at least the setting is turned on whenever I open a new instance of Maya, but if I ever close and re-open the GE in that Maya session the problem will return.
Expected Behaviour:
Choose the settings you like, save preferences, keep your settings intact until you change them yourself.