Yes, if an individual plant was planted by humans, it is cultivated, no matter how long ago the planting was.
There are many threads on the forum that might be useful. A sampling:
https://forum.inaturalist.org/t/when-is-a-plant-no-longer-considered-cultivated/12194
https://forum.inaturalist.org/t/do-i-misunderstand-the-wild-cultivated-distinction/31077
https://forum.inaturalist.org/t/wild-vs-cultivated-for-escaped-garden-plants/30432
But there are others as well.