StrateandLevel
The quote from NASA is correct. But if you read the pages linked to from the one you cite, you'll find that at no point do they use Newton's Third Law to assert that lift, drag, or total aerodynamic force is a 'reaction' to
gravity, which is what you implied.
B2N2
Now for the big question...
Does the 1st answer disprove or overrule the 2nd one?
No ....they co-exist.
They don't coexist at all. The assertion that the direction of lift (or total aerodynamic force) is perpendicular to the chord line is simply wrong, and you can see that it's wrong by either:
a) inspecting any drag polar and noting that D/L is not equal to the angle of attack
b) thinking about how that rule might work when you know that changing the wing span changes the drag coefficient for th same AOA.
The problem is not that it's a little inaccurate or not 100% correct. It's not even close.
If you want to claim that your rule of thumb is a good aide-memoire for those who don't understand mechanics then fine, go ahead and teach it. But it doesn't make the physics correct, or more importantly it doesn't make the physics
as correct as a proper explanation of induced drag!