وَالتَّخْصِيصُ لَازِمٌ لِلتَّقْدِيمِ غَالِبًا
Restriction commonly accompanies fronting.
The qualifier غَالِبًا matters: the source says restriction is common, not universal. Fronting can also answer demands of attention, strengthening, an opening formula, discourse rhythm, or verse.
It is therefore unsafe to insert “only” into every translation of a fronted object. Establish its scope through the audience, context, and other markers of affirmation or negation.