The RF 24-105mm F4 L was the first lens I got with the EOS R camera (the 35mm followed a day later) and I have kept it in my bag for over four years. Out of all my L lenses (currently: 14-35mm, 100-500mm; previously owned: 70-200mm F4, 15-35mm F2.8, 50mm F1.2) it is the one which performs the weakest... the 70-200mm was sharper, so is the 14-35mm while comparing the same focal lengths. With the 24-105mm I sometime miss focus where wouldn't´miss using a different lens, even after I sent to Canons repair center where they adjusted some glass parts...
I have been thinking about selling It for quite a while now, but what would the alternatives be? RF 24-70mm F2.8 is even heavier and more expensive... At the moment, I don't permanently want a gap between 35-70mm (or 100mm) or carry around more weight. Furthermore, I got the lens so cheap (799 €) compared to its current pricing... So, yeah, I'd love a mkii with better optical performance and maybe a little more focal length like Nikon or Tamron. Even 35-150mm sounds very intriguing.
So, yeah, my guess is definitely a mkii or a spiritual successor of the RF 24-105mm F4 L.
The RF 70-200mm could also benefit from a very small design change: move the control ring to the end of the lens as Canon did it with the F4 model. I guess that change won't justify a mkii version on its own.
For all other lenses I'd say: Unless there is huge improvement such as loosing a lot of weight or increase in FL or F number, Canon should focus on closing gaps in their RF line-up first.