Yes, computer belongs to employer thus "master password" allowed to secure PRIVATE area for browser passwords.
Lack of this functionality (master passwords) results (at least for me) that current version of Opera is useless (for me). I checked new Firefox (Quantum) – it is still supports “master password” so there are alternatives.
It is a pity that someone made such a strange (because of what?) decision (to remove this functionality).
Maybe you should implement a choice between securing internal Opera passwords by “system authentication” OR “master password” – leave user a choice instead force him to use particular scenario.
At the moment you force me to move away from Opera.