Display manager doesn't start after newest Manjaro update

Well .. sorta ..

The ‘splash’ removal was supposed to stop plymouth from running.
But then

(plymouth is the fancy boot splash that mainly exists as bloat, but sometimes as a boot breaker .. especially if one has missed kernel-mode-setting, or pacnews in general, but sometimes just because it feels like it)

If it were the same issue as previously experienced by users en-masse a bit ago, then you probably do have missing pacnews and/or unconfigured kms .. but also you could probably continue avoiding that by doing your upgrades again while allowing downgrade (spotfix for previously mentioned plymouth fallout)

sudo pacman -Syuu

Of course my 100% honest opinion is that you should kill it with fire permanently.