A better description would be "lactase treated" milk. In any case, I found consuming it regularly for breakfast still lead me to feel unwell over time.

However I can periodically consume dairy when I take a strong dose of lactase supplements.

From some literature it does appear that manufacturers can use "lactose free" even for non-zero amounts of lactose (10mg per 100g).

This is actually higher lactose density than many cheese varieties, especially considering I would be consuming say 150-200g of yogurt, whereas if I am eating cheese its in small careful quantity.