I do not know what you mean by “only have representatives from Bush and Rubio.”
Then you did not read the article.
This group of ‘power brokers’ from the GOPe had campaign reps from Bush and Rubio in on the discussions on how to broker a convention so Cruz or Trump is NOT the nominee. They are plotting. If it was to discuss how to handle a convention where there was no obvious candidate they would have had every campaign represented