Exactly. Down to the customizable HTML/CSS for profiles.
It would be such a hit of post-irony nostalgia that nearly everyone who was on it would jump back to it. We would get millions of users in a week, easy. All it would take is one Buzzfeed-style article "Remember the MySpace of your youth? It's back"
Then, showing the hockey stick growth, I'd sell it next week.
Another idea I thought of could be to retool the site into something different from simply a social network. I'm thinking of how the name could be used in a more literal way, while also staying in touch with the social-network angle of the site.
What about a platform where you design a Space, like a room you dec' out and build to your liking, using points or currency for upgrades/additions. A bit like the Sims where you'd build your "Space" and other users can come over and hang out. The living room could have an entertainment system which plays your custom playlist. DJ's could host live sets. On the TV is a Super Smash Brothers tournament you can get in on.
You might have a neighbor whose Space is the party spot, people go there and interact/chat with other people about, well, partying, or something like r/drunk. Then you might have another neighbor whose Space is a salon of sorts, people gather there to discuss the owner's recommended reading list or art collection.
A universe of micro-communities, or Spaces, as it were. Some are open access, some are invite-only, and some charge $5/cup to get in the door.