My ideas are this: Maybe you get tokens from doing stuff that involves friends (referring people, adding friends), and maybe any social activity? (forums, messaging, arena, selling/buying on Flea Market, anything that gets you interacting with others) These would be given at certain milestones (every ten forum posts, every ten messages, something like that), and would create a way that'd be easy for almost anyone to obtain.
Additionally, as we move forward, I think they could add things into the professions similar to how Flight Rising lets you share notes with friends in their Archaeology profession. So basically like, you could have friends help water/fertilize your plants, or dig faster when Archaeology is out, speed up cooking, send a wolf/companion to help with all someone's hunts (increases chances by level, maybe), or other things like that. It'd give you more ways to interact with your friends, and would reward Friend Tokens! (For both members.) All of these by just naturally playing the site. You could do it with anyone registered to your friends list. It would also give us a fun way to help out newbies, which would encourage them to stay. (Yay, friends!)
The important thing is to never lock content like this behind forcing people to have friends. Hence why I suggested any activity that interacts with the greater community. All of these activities should be optional boons for getting friend help, never a requirement. I see so many people on Flight Rising in particular who have maybe one or two people on their friends list (if that!), and they never post to the forums, but often still use the Auction House. I want to include those sorts of people in this, too.
I'm sure there's still room to workshop all this, but here's my ideas so far. The unfortunate thing about the current system is that there will never be enough new people to invite to keep it sustainable. Flight Rising has been around ten years, and still doesn't have more than a few thousand active players on the site at any given time (except during big events/announcements), and that's with thousands of accounts. I've also seen tons of mobile games try the Refer A Friend nonsense, or Exclusive to Friend Help stuff, and it's really hard to achieve, even with a built-in friend finder. So it just... I don't think this is a good direction. At all. Maybe with some tweaks. I hope staff will tweak it.
-----
Edit: Also adding more methods to get them and the currency for buying them lets staff add in more Friend Token items in the future without upsetting people. Imagine if we could get friendship sweaters or something!
Also consider: Gift boxes where you get a Friend Token for giving them, and the only thing you can do is give them to a friend, and then the friend can open them. Maybe you get one a day, or one a week, or I don't know. Randomly in Arena/Campaign/Gauntlet? Can craft them? Maybe craft them with one friend token and some materials? Buy them with friend tokens? I don't know???
Edit 2: Also these things would give different amounts of tokens, these aren't equal. Also friendship tokens could be sellable.