You weren't even allowed to touch the infrastructural M code. Mostly, you worked on superficial or peripheral M code, or on the GUI in VB6. I heard rumors of a GUI modernization team, but never saw any direct evidence of it.
It was a result of the iron grip of the top management. They didn't want to yield control of the company to the people actually running it. You were expected to use your expertise to do what you were told to do, in the best way you could, while still remaining completely within your lane.
After the 6 months of training, I gave it a year to read the character of the company, and then another 6 months to soak some potentially major family health care costs with that sweet insurance plan, then spent 4 months job hunting. It was the best employer-offered health insurance plan I ever had.
But make no mistake. Companies like Epic are why health care costs in the US are huge and growing. Epic never refactors anything that still works well enough to hold together with some expensive human labor. It is a technology company that runs on well-trained people instead of well-designed code and processes.