They should just stop giving a shit about douchebags who just want to farm their shit as fast as possible.
No matter the promo you can't force people to enjoy the game, they just need to accept that a certain percentage is just in it for the skins and will do whatever necessary to get them with as little effort as possible. I'm sure they've done some kind of analysis and have a good idea of what to expect, if their answer to "they're just farming AI games" was to force people into doing something they don't want to do (play with actual people/actually play the game) then that's a real dumb idea. The promo is not, I mean should not, be put together with those people in mind.
Another, different, percentage of people will actually give the game an honest shot because of the promo, those are the people you want to hook. But by forcing the the two groups to interact they sort of shoot themselves in the foot. The people who just want the skin have a bad experience and then that just ruins the experience people they're trying to actually hook, less people come away having an enjoyable experience, it's a lose lose .... forcing stricter requirements for the promo is counter productive.