I’ve written a lot about kitniot on this blog previously. To recap: Kitniot are not chametz, but they are avoided on Pesach by Ashkenazim as well because they may be confused with chametz or contain traces of chametz. Every year the discussion of whether these are valid reasons starts again.
Last year, one opportunity to re-start the debate was General consumer’s announcement that Cheerios are now gluten-free (which apparently was published already in February 2015):
Cheerios have always been made of oats, which are naturally gluten-free. Many farmers who grow oats rotate their crops. That means they also grow grains that have gluten (like wheat, barley, and rye). These grains get mixed in with the oats during harvesting and transport. To make Cheerios gluten‑free, we have to separate them from the oats.
This can of course be used to support the claim that the may-contain-traces-of-chametz concern may be relevant even today, this is a snippet from Cheerios Vindicate Ashkenazim! by Yitzchok Adlerstein, published on CrossCurrents:
Even today, apparently, grains get mixed with other grains, both in their growing (in the case of legumes, not through rotation, but as crops grown between the rows of grain) and in their transportation.
And of course the exact opposite argument made based on the same community announcement (comment by Menachem Lipkin on April 28, 2016):
Generally there’s little argument over why there was a need for the restriction when it started. They claim it’s no longer needed. The fact that a company the size of General Mills is able to make one of the most popular cereals in the world Gluten-free shows that it can be done on such a scale and certainly on the smaller scale of Kashrut supervision as is quite commonly done in Israel.
Elu ve-elu divrei elokim hayyim (Both [answers] are the words of the living God) !?