I am not sure that George Harrison exactly converted to Hare Krishna beliefs. Instead he was drawn to India for a time and studied with a guru there. It was probably among the first times that a performer let his spiritual preferences be known and it may have led the public to see more depth and to look for it.
Prior to George Harrison's conversion to Hare Krishna beliefs, a British performer named Cliff Richard's converted to Christianity, but his conversion went by vastly unnoticed by the public or society. In contrast when George Harrison converted to Hare Krishna beliefs, his conversion was viewed as a spiritual journey and was considered to be reflected in his music and bringing his musical expression to a higher level of maturity. This in turn provided evidence that celebrities served a greater role in society than simply playing their instruments, Celebrities beliefs did in fact influence the beliefs of the public or society whom followed those performers.
Although it was shocking when George Harrison joined a religion that was seen as unorthodox by
many in society it could hardly change the way that society views celebrities as a whole. There are just to many celebrities doing to many odd and varied things for one of them to have a significant
impact on how they are all viewed collectively.
No. I really do not believe that George Harrison's conversion to Hare Krishna beliefs changed popular opinion about the role of celebrities in society. At least not in any meaningful sense. By the time that happened, Harrison and the rest of the Beatles had become somewhat known for their Eastern philosophical bent.
George Harrison is a very popular celebrity and he does have a prominent role in celebrity culture. However, he has a right to switch religions if he wants and it doesn't need to be a big deal. I do not think that his conversion to Hare Krishna beliefs change anything.