Actualy that is compleatly false.
A phaser is baicaly a bandpass filter that is modulated by a LFO. Flange and Chorus are delay baised effects. You take the signal split it - delay it, and mix it in with the original signal. Chorus was created in the stuido originaly and it was called ADT (automatic double tracking), flange was also created in the studio by "placing your thumb on the reel" flange was born out of tape being out of sync. The only thing that seperates flange and chorus is that flange has regeneration, which causes the "jet" effect.
Thats why there are DOZZENS of flange/chorus pedals in 1 box and NO flnage/phaser effects... Phase is as different to Flange as a oven is to a microwave...
So, sorry you are so very wrong.
Alex