I have confirmed that Canon is still on schedule to release new firmware for the Canon EOS R5 in November, I was unable to confirm the same for the Canon EOS R6.
Here’s a reminder for what to expect for the next Canon EOS R5 firmware.
Canon Cinema RAW light addition
1080p @ 120fps
Further tweaking of temperature control
Other codecs are being worked on, but may not arrive in time for the November release.
I have corrected the post, I previously mentioned C-Log 2, but that is not confirmed.