A couple problems with this
1) just because you own friendster.com doesn't necessarily mean someone else doesn't own the Friendster trademark. He might get contacted by a lawyer soon if/when such owner notices someone is trying to bring it back to life.
2) requiring tapping phones to add friends is fine in theory, but that really limits your social circle. How do you connect with friends who have moved away, or just don't see that often? You might still consider them good friends, talk to them on the phone, engage with them on other social media to stay connected in each other's lives, but there would be no way to add them.
I think he'll have to compromise on the tapping phones thing. Maybe have a different category of friendship for those (give an "in person" star for people who you have tapped to verify friendship or whatever) but you gotta have a way where you could for example post on Facebook "hey I'm on friendster if you are too add me there" to build your circle. Otherwise I'd have to ask people in see in RL "are you on friendster?" and when it is getting off the ground 99% of them will say "no" or "what's friendster?" or "I don't need yet another social media account" and it just isn't going to be able to build a network. If I joined and I had only five friends on it I was able to add in person I'd never use it because it would be boring as hell and it'll never reach critical mass.
And how is he planning on keeping this going if it catches fire and there are 100 million users a year from now? You gotta get revenue somehow, unless you are independently wealthy, which I assume a "Philadelphia area programmer" is likely not. So either you bring in outside investors, who will demand some way to make a return on their investment, or you will have to find a way to make a return on it yourself.
Now in exchange for some type of enforceable ironclad guarantee that it would never have ads or 'sponsored' stuff where you see content not from your friends (or perhaps friends of friends) I would be willing to pay a buck or two a month if I became a regular user of this. Would enough others be willing to do so though? That's the only way you can make a go of it without advertising, which guarantees eventual enshittification.