KGI Securities is expecting Apple to launch a new MacBook Air sometime in Q2 2018 with a lower price tag. The analyst firm does not offer any details as to how much of an upgrade will the new Air be but obvious internal upgrades inline with a 2018 notebook can be expected.
https://www.notebookcheck.net/KGI-Low-cost-MacBook-Air-13-coming-in-Q2-2018.287326.0.html