Thanks for pointing that out. I don't have a good understanding of the Rwandan genocide, so I can't really speak to it, but of course I don't care to diminish the suffering of any group of people.

Here's Engler's article that seems to be the cause of concern. https://yvesengler.com/2017/09/22/statistics-damn-lies-and-the-truth-about-rwanda-genocide/

From what I can tell, he doesn't deny the genocide, but he does claim that the narrative around it was manipulated to benefit western powers.

Praise for Dallaire’s role in Rwanda is based on a highly simplistic account of what transpired in 1994. In their haste to promote a Canadian saviour in Africa, left/liberals have confused international understanding of the Rwandan tragedy, which has propped up Kagame’s dictatorship and enabled his violence in the Congo.

When commentators are claiming more Tutsi were killed than lived in the country it’s time to revaluate popular discussion of Rwanda’s tragedy.

Engler's blog post was from 2017 and it seems, according to Wikipedia, his claims have gained more backing from others: https://en.wikipedia.org/wiki/Rwandan_genocide#Death_toll_and_timeline

The succeeding RPF government claims that 1,074,017 people were killed in the genocide, 94% of whom were Tutsi. In contrast, Human Rights Watch, following on-the-ground research, estimated the casualties at 507,000 people. According to a 2020 symposium of the Journal of Genocide Research, the official figure is not credible as it overestimates the number of Tutsi in Rwanda prior to the genocide. Using different methodologies, the scholars in the symposium estimated 500,000 to 600,000 deaths—around two-thirds of the Tutsi population in Rwanda at the time.