Looks to me there are 2 general arguments:
1) Aluminium house wiring was a disaster, so it’s bad and unusable.
First, house and car wiring are very different. House wiring normally uses solid conductors and connections made on site with various methods such as twist nuts, backstabbing, wire under the head, etc.
Car wiring normally uses twisted wires and crimped connectors most of time, and the connectors are often attached in a factory, especially in case of thicker wires such as battery cables, etc.
Second, over 50 years elapsed since since aluminium wiring went back to copper, and that was more than enough to find solution to the issues that initially plagued aluminium wiring.
Lastly, most likely only thicker gauges will be replaced since that’s where the major savings are, and thinner gauges will stay copper.
2) As for the safety argument, seems like that’s largely based on experience with house wiring and FUD, and since today’s automotive wiring is very different from the late 60’s early 70’s house wiring, that largely doesn’t apply. Furthermore, so far there is no evidence that Al wiring in cars in overall would be prone to the issues seen before.
