I doubt the Admins here would approve of this if it is not legal. Why don't you get permission from the creators?
If he got permission from the creators he may get in trouble, as he already downloaded pirated copies of the games, unless if he deletes them.
And I believe it's the creators decision whether to re-release them for free (legally) or paid.
As I said on the other thread though when it comes to Nintendo games though, if they catch anyone uploading illegal games, they can get fined massively and they will remove emulated games when they find them.
I will mention though.
There are legal ways to get some old Nintendo games though, you can buy them 2nd hand, and there also some classics that Nintendo have put up in the virtual console in the Nintendo eShop, if you have a 3ds, Wii U or Switch, that only cost a little bit of money, there are also the SNES classics and NES classics (which can be picked up for 2nd hand) and Mario and Zelda Game & Watches, as for PlayStation there is the PSOne classic, Sega also released some classic consoles a few years ago, but Sega also have games that they put on the Android play store which can be downloaded for free with ads or paid for to remove ads, most old games though can be bought 2nd hand.
From my understanding though, if a game has been put up for free without the creators permission, then it's most likely illegal.