The main thing is that it's never valuable to exactly replicate a study, from a commercial, career or publication perspective. Other studies may 'incidentally' cover the same ground, but then there are any number of variables which can explain why "this seemed to be different, but".
That being said, numerous papers have been published undermining the 'amyloid beta as primary disease driver' theory already. Or at least, finding no statistical correlation between AB and neuron death or that sort of thing. The most valid hypothesis that I've seen is that AB is just a supporting element for another amyloid, tau, which does correlate with toxicity.
It's not even the toxic oligomer hypothesis that is undermined - it is only the role of amyloid beta as a primary driver of Alzheimer's pathology. This isn't even out of nowhere, there's been plenty of data finding no strong association between AB levels and pathology. Most data seems to point to AB being more of a supporting element, with tau amyloids actually being associated with toxicity and resultant functional deficits.
That being said, numerous papers have been published undermining the 'amyloid beta as primary disease driver' theory already. Or at least, finding no statistical correlation between AB and neuron death or that sort of thing. The most valid hypothesis that I've seen is that AB is just a supporting element for another amyloid, tau, which does correlate with toxicity.