He’ll be fine with any dog. He doesn’t sound like he wants a certain breed, so I’m sure he’ll fall in love with this dog as well. As he just wants another dog as a companion, I’m sure he really doesn’t care that much about what breed or what dog it is.
My GF didn’t have a lot of say in our first dog being a GSD. But she loves him more than anything and he’s actually “her dog.” Our second dog also ended up being a GSD because she needed a home, my GF has wanted to rescue a pittie for the longest time but knows we’re a two dog household so she realizes that due to this second dog, she won’t get her dog for at least a decade now. But she loves this dog just as much as our first one and this second one is exactly what my GF wanted, a huge cuddler.
Basically, unless he was really wanting to get into IPO or something where a different working dog is a better pick, I’m sure he’s not going to mind where the dog comes from. If he does decide that he wants to raise this one, if I were you, I’d step back a little and let him make this dog “his.” That way he’ll feel a much bigger connection to this dog than the one you have now.