Please see this video from Canon USA, which was specifically about the video features of the R5:
You only have to go 10 seconds in to see pesky asterisk #2, which states:
"*2 8K movie recording (RAW, DCI, UHD) has restriction on possible recording time due to camera internal temperature rise. Max possible recording time is approx. 20 min. (at room termperature)."
This video was released on July 9, 2020, which was the day the R5 officially launched. This was LONG before all the internet drama about overheating. Note that they specifically said "
MAX" recording time in 8K was 20 minutes* at room temperature (emphasis mine).
There was no deception. There was no burying it in the manual. It was, like EVERY other feature in Canon's videos that summarize main features of a new release, asterisked with real-world conditions that support the claim of the highlighted feature. I wish all the YouTube "experts" that decry Canon's marketing would stop perpetuating the myth that Canon promised one thing, then delivered another.
The irony is that so many starry-eyed "influencers" missed the informational "stars" all throughout the presentation.
* And with Firmware 1.1.0, people are getting more than 20 minutes. So Canon not only delivered what was promised at launch, they managed to give even more within a few weeks.