It's not at all clear why loading vesafb from the initramfs would have any effect, given that /etc/init/udev-fallback-graphics.conf should already ensure that vesafb is loaded before plymouth starts. It's possible that vesafb needs to be loaded *before* the nvidia driver to have the necessary effect; that seems to be a change from past behavior of the drivers.
It's not at all clear why loading vesafb from the initramfs would have any effect, given that /etc/init/ udev-fallback- graphics. conf should already ensure that vesafb is loaded before plymouth starts. It's possible that vesafb needs to be loaded *before* the nvidia driver to have the necessary effect; that seems to be a change from past behavior of the drivers.