Perhaps you should read the context of that verse.
The Bible speaks of the church as Jehovah’s flock (Acts 20:29; 1 Pet 5:2). Up until the conversion of Cornelius, the Gospel invitation had NOT been made available to the Gentiles. But that changed suddenly about AD 36. Of the conversion of Cornelius’ household, we read in Acts 10:45, “And the faithful ones that had come with Peter who were of those circumcised were amazed, because the free gift of the holy spirit was being poured out also upon people of the nations.” NWT.
The gentile Christians could not be invited until after the 70 weeks (Dan 9:24) for Israel were completed (AD 36). Of that final week [a day = a year], we read “And he must keep the covenant in force for the many for one week” Dan 9:27 NWT). That covenant was Jehovah’s 70 weeks agreement with Israel. It was in the last half of the 70th week, three and a half years after the cross, that the great work was done amongst the Jews.
Applying the “other sheep” to the new gentile converts is the evident meaning and it would take strong additional scriptural evidence to convince the honest student otherwise. There is no direct indication in the Bible that these “other sheep” are referring only to the “Great Crowd” (true Christians who will not be part of the Little Flock.” Another reasonable application would be to apply this to the billions of mankind that will be awakened from the dead in Paradise earth and there have an opportunity to follow Jehovah in obedience forever. Without further compelling evidence, applying the “Other Sheep” to the “Great Crowd” is building a doctrine from a scripture taken out of context. This reminds us of the Catholic Church misapplication of Matt 16:18 which says, “You are Peter, and on this rock-mass I will build my congregation, and the gates of Ha’des will not overpower it.” (NWT) Based on an unsupportable misapplication of this text, the Catholic Church believes that the papacy represents an “unbroken” line of apostolic succession from Peter to the present day.
