Yeah, you want to avoid putting your system through a shock by introducing too much nutrients at once while malnourished.
Granted, it sounds like the villagers weren't eating nothing. Just very little. All the same, ideally Van should've done something like...
1. Prepared warm stew with the boar meat, along with maybe some milk and fruit for their first day.
2. Give them a hot bath so they can get comfortable while you assign homes so they can sleep off their exhaustion from the journey.
3. The next day, feed them more stew and check them all for any signs of unstable conditions like lethargy, headaches, or dizziness. Spend the day hammering out the details for their migration and getting them any other living necessities that might be missing.
4. If they're still weak, more soup and stew for the evening. If they've regained their energy and have calmed down, then we can have a big ol' welcome barbeque.
It can take a few days to ease out of the danger zone, but that's usually for people who have gone off zero food for days.