As far as I know this isn't the first time Arsenal have done it , few seasons ago they did the same but after the middle of the season they lost all power even though they are still playing with the same squad let's see if Arsenal repeat it again.
Not everything has to be the same as last season at Arsenal, because last season there weren't many players who were consistent and productive enough in every game so Arsenal's performances didn't look so consistent last season. Whereas this season I have seen that there has been a slight difference in appearance since the presence of Gabriel Jesus at Arsenal's front line who was very productive using every pass that was aimed at him.
This season the Arsenal players are in good shape in terms of game consistency. their performance also seems to have not decreased so far this season. but still can not be denied that in every season sometimes there is always something unexpected. like there are times when a team that was originally consistent becomes inconsistent from the middle of the season. and on the other hand there will be teams that started badly but they changed for the better from the middle of the season to the end. But this season's arsenal is a little different. they performed better than last season.