When GH devised Copilot, they could have (internally, at GH) decided to make a two-tier model, one tier trained only on unrestrictive licenses, the other bringing in more-restrictively license code too. And then offer them to the GH-using public as two different functionalities. An intelligently differentiated product line for intelligent people.

But: NOOOO.

In order to close off this possibility, which would restrict Copilot revenue, they instead would roll out a single undifferentiated product and with lots of "gee whiz!" and associated hooplah, and be sure to offer it for free for a while to suck everyone in and head off criticism.