No it is not 😊
Well, I can see now why you are so confused about what exposure* is, what does and does not affect it, what noise is and what does and does not affect it since you hold that error laden article in such high esteem.
That article states early on that
"Exposure is the amount of light that reaches your camera’s sensor, creating visual data over a period of time."
but then loses all credibility when later on it states
"You can also adjust exposure in post-processing."
Perhaps you can explain to any beginners who might have the misfortune of stumbling across that article how on earth can you adjust the amount of light that reached your camera’s sensor after the shutter had closed, let alone in post processing?
The author seems to be confusing image lightness and exposure* which, although related, are two different things. There are other incorrect statements in that article but the above is the main one that discredits the article.
You can alter the image lightness in camera without adjusting the exposure* at all.
A much more accurate article on exposure and ISO is dpreview's Richard Butler's 2 part article.
Richard Butler's article effectively debunks the vast majority of that Adobe article.
* exposure - amount of light that struck the sensor per unit area while the shutter was open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights.