Yes I believe these are genetic defects. Even the synonymous mutations that code for the same amino acid can affect protein folding or production rates, so there are probably no truly neutral mutations. The vast majority would be mildly detrimental. Natural selection is a real thing but from my reading can only remove about 1 mutation per generation; hence the question “why aren’t we dead 100 times over?”. Most of the mutations would be mildly deleterious but below the selection threshold. The significantly deleterious mutations are probably those that cause spontaneous abortion and never get born.
According to Keightley P, Lynch M (2003) “Toward a realistic model of mutations affecting fitness”. Evolution 57:683–685. “In summary, the vast majority of mutations are deleterious. This is one of the most well-established principles of evolutionary genetics, supported by both molecular and quantitative-genetic data.”
Based on this I think it is a reasonable inference to estimate that the genetic load has increased by 10,000 defects over the last 2,500 years. (OK so you could allow for 1/100 mutations being removed per generation and get 9,900 defects)
I watched the video and I think it is quite superficial. It seems to be attacking a strawman version of YEC. Since I don’t have Matlab I can’t check the program itself. From what I can see in the video the program is about as superficial as the video. I suggest a better reference would be “The fundamental theorem of natural selection with mutations” Journal of Mathematical Biology, June 2018, The fundamental theorem of natural selection with mutations | Journal of Mathematical Biology