it is one logical pathway, but another is to simply move to a new area, rather than develop animal husbandry. Which one seems more likely?
Both at the same time. If you repeatedly migrate in order to maintain a foraging and hunting lifestyle, you are sufficiently aware of the undependability of foraging and hunting to make large R&D investments in experimental methods of agriculture and animal husbandry.
Depends on how many science points and settlers you have, and where you are on the rest of the tech tree.