Chelsea is not a champions League title contender because they don't have the squad depth to do that as their players are young and inexperienced I know that most Chelsea fans are carried away by their recent success but that should not deceive them.
I think it is too early to exclude Chelsea from the UCL title competition. At least, we must take a look first of few early matches in UCL. If Chelsea can get positive results in UCL league matches, why don't expect them to compete for the title? However, usually we are talking about the chance of winning the title when the UCL reaches the quarter or semi final round. In this stage, we can see which team to have a bigger chance.
Regarding the young players and inexperienced in UCL, I think this isn't a very big deal. They have a coach who can manage them. If the coach can apply a proper tactic, they must also can play well.The champions League comprise of the best teams across Europe and will need more than just a young team with to win there is a whole lot of things to consider like having the right winning mentality, experience etc which this present Chelsea team doesn't have
Of course, UCL is the competition of all strongest teams in Europe. So, it is difficult to win the title, it is mostly for an established team only. However, it is not impossible for a surprise. We must know that we often saw many surprises in UCL. That's why I personally don't want to exclude Chelsea too early from the competition of winning the title.