Welcome to the forum, and I hope well for your son and the entire family! It is very encouraging to see you here, thank you!
There are many diabetics on this website who manage their life very well plus are examples not only to their own community but to non-diabetics as well.
To answer your question, there is the ‘honeymoon phase’ when from a few months to a few years, a newly diagnosed T1D’s pancreas could still be producing some insulin and other hormones viz. Glucagon, Amylin, etc.
In my case, its pretty much dead since a few decades i.e. its not making any of the hormones required to regulate and convert glucose into energy and hence the hyperbole- useless.