Yes, unintentional side effect. I'm sure it crossed the minds of some the executives that they might be screwing their competition by buying out all the chips.

Apple is obviously not going to buy less so their competition can have more when Apple needed the supply.

Intentional effect.

The fact that it's one of severel effects and one of several motivations does not make it unintentional, or even necessarily just a side effect.

It could just as well be simply one of multiple fully considered effects, and surely was.