They're more than just rumors. They are directly stated by Canon that they are considering implementing them. Because it's straight from Canon, and not the rumor mill, I think it can be inferred that it's definitely coming, barring some extenuating circumstances.
I don't know where it is on the English page, but on the Japanese page it is as follows:
ファームアップでの対応を検討中の内容に関して
- フルHD/120Pの記録サイズ対応
- すべての解像度およびフレームレートのRAWとIPBに低ビットレートモードを追加
- Canon Log 3
The link to the page is
here (Japanese; Canon USA seems to be down at the moment due to the ransomware attacks I imagine). It was also discussed in
this thread.