According to Automotive News, the potential $1.3 billion project will be related to battery production and new EV production (a new Ultium-based model).
Orion Township will offer a 12-year tax break on the new facility (a 50% reduction in property taxes), beginning in 2026, when the new facilities are ready. There is a potential for 2,000 new jobs at the site by the end of 2028.
"Orion Township's board of trustees on Tuesday approved a 12-year tax break for General Motors to launch a $1.3 billion expansion of its Orion Assembly plant for production of EVs and batteries."
The question is whether GM really will decide to proceed with the investment and when it will be officially announced.
It's currently not clear what electric vehicles would be produced at the site. GM has many Ultium-based EVs in the pipeline. One of the rumors was hinting at electric pickups, but it could be a Bolt EV/Bolt EUV sized car as well.
The issue is that the 2026 year is quite far away. Maybe a new project will be launched earlier than that?
At this point - 2023/2024, the Chevrolet Bolt EV/EUV would potentially be obsolete/not competitive with the newer GM products.