Is a job offer enough to prove intent to depart for a U.S. B2 Visa?

[bendre18]

My partner who lives abroad in Portugal (Brazilian National) would like to come visit during the upcoming holiday season. He currently doesn’t hold a steady job as he does a lot of side jobs (handy man) but his mom plans on sponsoring his visit. He has a job offer that is set to start in January and plans on starting school part time once he returns to Portugal 10.0.0.0.1 as well- I am wondering if a signed job contract and school enrollment for the upcoming year would be sufficient to prove his intent to depart from the USA after his trip? Thank you!