Not necessarily. The word just means [trans]port to another platform. It's only relatively recently that writing automatically portable code has been possible, and even then there's usually some modification involved, otherwise we'd just call it "recompiling".
It has been used this way in relation to games for years. Game ports of the 80s and 90s very often involved complete rewrites from the arcade version, sometimes without access to even the original graphics.
I remember reading accounts of ports where the porters were not even given a spec of any sort, but were lent an arcade cabinet of the original and had to essentially test there way through everything to figure out what to implement.
I wanted to emphasise trying to stay as close as possible to the original as possible, while still being a C64 game. I didn't have access to FB source, so it's just reverse engineered. It's still in need of tweaks and fixes tho (I spent 2 days on it).
It has been used this way in relation to games for years. Game ports of the 80s and 90s very often involved complete rewrites from the arcade version, sometimes without access to even the original graphics.