Sure there is—it is my experience as a website operator and as someone familiar with the field of website operation that architectures like theirs are more common than architectures unlike theirs. Professional experience is a (highly compensated) form of gathering data.
And I’ve got 20 years of such experience that concludes their architecture is less important than the fact that they simply ran out of peak capacity; and that we do not know how many sites operate so near capacity for us to conclusively determine whether a majority of them are at risk.
