I mean the desync is probably just cause the audio in the Camila video was encoded once for the video, while the audio from Evil Neuro is encoded once for her to "sing", then the audio output is re-encoded again for the stream, then ripped by a clipper/vod backup channel and possibly re-encoded another time for upload to RU-vid. And if there's any change in sampling frequency along the way it's going to desync.
not really. changing sampling rates will at worst add "wobble/distortion" but it will not change tempo. (bpm) - Realistically, it will change nothing, except if you de-and-re-compress it at each step you lose some quality. Not tempo.
If she wasn't it would be pretty sad for vedal, the tech for evil is better than the simple tts that neuro has. I can't wait for neuro to finally upgrade her voice.