Answer: it indicates that chances for success are good. Check this (link) for the full story. The article's specific takeaways:
- 5 star transfers usually perform well
- Offensive fit matters a great deal
- Immediate improvement over the previous QB and general production is possible
It's a pretty small sample size, and a more granular review from Brian will be more helpful, but I think this article is reason for some cautious optimism from a non-OL perspective.