If you use agplv3 for training your LLC, shouldn’t the code you spit out also be agplv3?
Only if you can reasonably argue that the output is the input (even with exact matches over a certain size being auto-rejected), and that it is enough to qualify as a copyrightable work. I’d argue line completions can never be enough to be copyrightable, and even a short function barely meets the bar unless it is considered creative in some way.