Let's see how it turns out. Abrar Ahmed is not a newbie and he has played sufficient number of matches against other international teams. The spell of 4-0-9-4 was simply astonishing, when the other bowlers were going for close to 10 runs per over. Pakistan is yet to resolve their shortage of quality spinners. Abrar is good, but I am not sure whether he will be able to perform consistently like Saqlain Mushtaq, Danish Kaneria or Mushtaq Ahmed. If he is able to do so, then it will be good for Pakistan.
Abrar Ahmed test stats are good but he is yet to prove himself in T20I. Before this games, Abrar has picked just 17 wickets in his 14 matches. If Abrar want to be permanent part of Pakistan T20I squad then he need to improve his T20I squad. Saqlain, Mushtaq and Danish played cricket when their is only ODI and Test, while today T20 is the most played format. It's difficult for part time spinners to survive in this short form, only genuine spinners can bowl and pick wickets in this format.