Then they were never real fans in the first place, just bandwagoners. A lot of BTS fansites also closed and switched biases when W1 debuted. It's normal.
True, then there will be plethoras of new fansites opening even in their 6th year now for BTS. I still saw many new fansites opening for BTS' members. It's the cycle of life, some come and go. We didn't care when those fansites change their acc to W1 fansites. We didn't care now. People can always unsubscribed and unfollow when they realize that those fansites and youtubers are just bandwagoners later.