Canon should recognize, that they cannot stop that near-future MILC cameras will be easily capable of 8K 120p raw, etc. The market of high-end cameras will be partially cannibalized by lower end solutions. They should concentrate on selling as many RF lenses as they can, which they can do by offering great products at every level.
This chart is very interesting from DPreview user Jesse. It clearly shows, that HQ mode doesn't produce a lot more heat, than normal mode. The temperature plateaus around 59-61 ℃, but then it stops rising. HQ mode is actually barely hotter than normal mode, it still shuts down.