/etc/modules-load.d can only load modules, nothing more. You can’t blacklist a module and you can’t insert a module with special options.
In /etc/modprobe.d you can blacklist a module, you can crate an alias for a modulename and you can add special options for modules.
So basically /etc/modules-load.d can be used to insert a module at boot. /etc/modprobe.d cab be used to blacklist or adds options.