I actually do not think this is the ideal debut for Roger Gracie for two reasons.
1) Why make his debut in the US? This is honestly the venue where he will atttract the least amount of attention. If this match was in the UK, it will fill Wembly Stadium, it could be the biggest MMA show in Europe ever. In Japan he would be fighting in front of tens of thousands in the most highly anticpated debuts ever there. In Brazil it would be front page news. Here in the US, they will struggle to sell to 50% capacity. I'm sorry, but the Gracies name in this market has gone way down with some very high profile losses. Roger Gracie is less of a draw to mainstream American audiences than any contestant on the Ultimate Fighter. Think I'm wrong? Witness the only sites which are reporting on Roger's debut are JiuJitsu based ones, the story is untouched by the more MMA based sites such as MMAWeekly, Sherdog, and Maxfighing among others. Furthermore, sport BJJ champions have proven to be lacklaster draws in the US as of late, including Gabriel Napao and Pe de Pano.
2) Don Frye may be past his prime, but he is still an extremely dangerous opponent for Roger Gracie. Roger would have been much safer picking a grappling based fighter for his first opponent. I can say with confidence that any Roger would have a distinct advantage over any\one who prefers submissions. The trouble is, Don Frye has no intention of going to the ground, and I'm not sure if Roger can take him there. Roger's takedowns are suspect (pretty much the reason why he isn't a three time Mundial Absolute champion) and Frye is a pretty good wrestler. A striking contest is going to heavily favor Frye as well. Plus Frye has a definite experience advantage and a probable strength advantage.
Don't get me wrong, I am rooting for Roger, I think a win for him would be good for jiu jitsu. But I am not thrilled about the circumstances of this match up.