Practically speaking everyone knows what you're talking about regardless of the term you use, but you're not correcting anyone when you replace the more precise

Practically speaking everyone knows what you're talking about regardless of the term you use, but you're not correcting anyone when you replace the more precise term microgravity with the less precise term zero-g. The ISS is in free-fall around the earth but there is also a tiny amount of atmospheric drag and tidal effects from other bodies like the moon- it is not zero g.