Thanks for reading the article 
. Yes, I have heard this line of reasoning, and it may have some validity. I prefer to not assume this is the case right off the bat though.
There have been times where core Buddhist teachings have been dismissed as ‘late’ by well known scholars. For example, the four noble truths are considered to be a ‘later development’ on Wikipedia; see below:
Based on Wikipedia, awakening is just the attainment of jhana.
Having analysed the arguments of the authors, I found them lacking. The second post found at this link is an analysis I did on Dhamma Wheel showing that the four noble truths could not be dismissed as ‘late’.
This is just to say that attributing the variability in suttas to their ‘earliness’ or ‘lateness’ and then dismissing the ‘late’ ones should, in my opinion, be used as a last resort. As seen above, it is possible to destroy the heart of the teaching in by excluding or distorting a sutta using faulty logic; thus my attempt at resolving the variability using my present approach.