For me the question is how far the superstars serious to involved and care about cryptocurrency because all i know they joining crypto world mostly invited or promote their own projects related to crypto and i think they not so different such as most people when joining that they targetting huge profit and maybe big possibility when they lost they will leave it so in my view superstars joining crypto or not it does not have huge impact for crypto world
There is always a stage for everything, the stage of awareness comes first before adoption in cryptocurrency, even if they are being paid as form of advert or so, let them get to do so, from there, they themselves will learnt about Bitcoin and its usefulness to the community.
When the adoption time comes, it will not be a new thing to them, and adoption by these celebrities usually comes in large form, because they are super rich and when they decide to invest, it will be in large sum of money they can easily loose, so their coming in will really help the market move up further, although not completely, but at least, it will still have a significant value.