I think any first reaction is always an entirely fair first reaction. Biases exist. Snap judgements exist. No point in pretending otherwise.
I think like with anything "new", life is always about disconfirming our biases. As a result, now that you're aware of this bias, have the additional time and can access System 2:
Going forward you find a way to have a less aggressive reaction to learning about a the next VTuber.