This is what some people are misunderstanding because Newcastle won against Liverpool in the Carabao Cup domestic, meaning Newcastle are strong enough to win against any other top club that they will be meeting in their matches. The Champions League is a different competition, and there are top clubs there that Newcastle cannot even challenge when they need the clubs you just mentioned now to beat Newcastle in the Champions League because I know the clubs you mention cannot allow Newcastle to take over.
We know that this victory isn't an absolute terms for judgment as it regards the strength of Newcastle but then they aren't doing bad either and I believe that victory will help their confidence a whole lot than it would if they had lost and so even in the Premier League they shouldn't be considered any less at this point because they obviously may surprise those who try to consider them any less and will get luckier than expected just like they have been against Liverpool in the carabao Cup. They are one team I don't consider weak completely but see them to come through with so many possibilities actually because they are capable of using opportunities when one shows up.