I believe that Arsenal still looks strong so maybe it won't be like other years, maybe they won't start to get worse. Doesn't mean that they are going to win everything, they could still end up with a loss, we should just consider that Arsenal has stayed longer than last time and seems to be going strong, didn't lose any games in a while as well.
I think this could very well be their season. Of course they could fail too, there is no shame in that, they have two very big competition and both Liverpool and City will do their best to win it as well, doesn't mean that whoever loses ends up being bad. People do not remember the second place, or how you got the champions title, they remember who won it, so only thing matters is the end.
Arsenal's performance this season is indeed very extraordinary and even they can be a strong candidate to win the Premier League this season, but still I doubt their consistency can last until the end of the season, because I see last season consistency make the cause of Arsenal failing to win is because their consistency began to be disrupted towards the end of the season and as a result they could only win the runner up position last season, It's not just last season but consistency is actually Arsenal's disease, even if we look back of course we can see how Arsenal continue to fail due to their performance ups and downs, and hopefully this season we won't see Arsenal's illness recur this season and make them extend the title drought.
What you are saying is very true, for now Arsenal can be top of the table but the question now is whether they can last long?
Tomorrow's game will be a test for Arsenal, because currently Aston Villa has a pretty good performance, so it might be a stumbling block for Arsenal in maintaining the top of the table this week.