Breast augmentation involves increasing the volume within a specific breast skin envelope. Small breasts can have either large or small areolas, and everything in between. Depending on how much small breasts are enlarged (the size of the implants), the areolae will stretch to some degree. The amount of stretch also depends on implant placement (either above or below the muscle), the thickness of the muscle (if below), and the patient's own weight (thickness of subcutaneous fat layer). Even breasts that start out reasonably large will show some degree of areolar stretch if the breasts are enlarged further!
Another major factor is whether or not the woman was previously obese and lost weight (such as gastric bypass patients), or had babies and breast fed, losing breast volume while having had previously-stretched areolas. Re-filling a "deflated" skin brassiere will certainly enlarge a contracted areola.
Plastic surgeons know this because we (at one time in our training or experience) create skin grafts. When we cut out a circle of skin, the donor site stretches, and the graft contracts. This is because skin is elastic. Thus, a smaller less-stretched-out breast will require some skin stretch (including the areola) if the volume it encloses is increased (or if a fixed volume is kept within a tightened--lifted--skin envelope). Some may have just forgotten this.
Your first photo example underwent periareolar (Benelli) skin tightening, and appears to have unnaturally-large anatomic implants (or capsular contracture causing firm distorted breasts). It is impossible to ascertain what her areolas might have looked like prior to her augmentation because of the periareolar scars.
The second example is both disproportionately large and over-augmented (except for a porn star) and "bottomed out" with nipple/areola complexes that are too high on her breast mounds, but still quite small in diameter. I would suspect that she had inordinately small areolas prior to her augmentation, but can confidently assure you that they did indeed stretch some!
If you click on the link below, my website shows 31 breast augmentation patients (before and after photos) in our practice, each of which provides age, implant size, and often how many children each has had. You can clearly see that anyone who says that areolas "don't stretch" is basically not checking their patients very closely, or has forgotten their training, since virtually every augmentation patients show some degree of areolar enlargement as their breasts are enlarged. Of course, some stretch more, and some less, but to say that it doesn't occur is inaccurate.
You can also see that the smaller pre-op areolas appear darker than the stretched post-op areolas. This is another physiologic fact we learn from our skin graft training (and something we employ when performing areola reconstruction after mastectomy). The reason this happens is that same number of pigment cells is present in the areola before and after augmentation (assuming no surgery on the areola, just implant placement), but when you have the same number over a larger (stretched) area, the pigmentation is less dense and appears lighter. You can see this is the patient photos where the pre and post-op color matching is good. This is another "proof" of areolar stretch.
Age, weight, previous weight, pregnancy status, breast-feeding status, previous breast size, implant size, implant position, and genetics all play a role in determining just how much an individual patient's areolas will stretch. This is too many variables to make an honest and accurate prediction, but areola stretch will always occur! There is no technique that can prevent this, nor will submuscular placement eliminate stretch from occurring. Best wishes!