Is it a scam, in a word no.
Apparently when you contract with a talent agent most people assume they will get a call, that simply isn’t the case. However, by being a contracted talent at least your hat is in the ring.
If you were to go to One Source Talent and ask for representation of course they are going to assure you that they have plenty of auditions coming up, and tons of contracts for talent, they do, it’s true. Are you going to get one of these jobs, or even a call for an audition; hard to say.
It’s kind of like buying a lottery ticket, if you have a ticket you have a chance of winning, without one you aren’t even in the contest. So, if you want a shot at being a professional model, actor whatever, you should trust One Source Talent.