The issue you faced with kernel 6.7.0 is actually a mkinitcpio issue [1] that made initramfs files grow up in size significantly. Fortunately, this issue already has a patch already tested and merged. [2] :) As detected a moment ago, the current git mkinitcpio version still does not resolve the issue. I am ending up with 5× inflation of the image between linux 6.6.8 and 6.7.0. So the problem remains open. A correction/clarification on the current situation.
There are two factors at hand. One is 6.7.0 introducing nouveau with GSP.⁽¹⁾ The other is an issue in mkinitcpio. They both contribute to image inflation and, independently, the latter is triggered by the former. The commit mentioned by Robin Candau fixes the latter. Upgrading to mkinitcpio 37.2-1 *does* reduce image size for people, who experienced its increase due to the symlinks issue.⁽²⁾ Separately, regardless of the mkinitcpio fix, pulling in nouveau in 6.7.0 still causes the image to be bigger. But this is not something mkinitcpio may address at this point. ____ ⁽¹⁾ https://www.phoronix.com/news/Nouveau-GSP-Merged-Linux-6.7 ⁽²⁾ Not all do, which led to the mkinitcpio fix to appear ineffective.