This is just getting silly. Again, re-read the definition of nepotism:

Nepotism, the unfair practice of granting jobs and other favours to relatives, whether by blood or marriage.

Passing along Jack’s name to producers, casting agents etc is a favour which is being granted simply because of who his parents are. Which is exactly the definition of nepotism.

Secondly, someone having opportunities that others don’t based off of wealth isn’t nepotism.

Sure, if Meg Ryan paid for extra acting classes etc, that’s a different type of privilege. But, her passing along his name to folks on the basis that she’s his mom, that is nepotism.

Look at literally the first example of definition of nepotism:

In education, nepotism occurs when the children or relatives of wealthy or influential people are admitted to elite schools (known as “legacy admissions”). It can also occur when they receive better grades and more opportunities primarily on the basis of their family connections.

If his mom is passing along his name and giving him more opportunities primarily based on being family, that is nepotism. I’m not sure how to break it down for you any further. You can insist that Britannica is wrong but that just seems silly.

Edit: Handy link so you don’t have to hunt for the definition