[theme-reviewers] Deregistering mediaelement style / script

[Afzaal]

Hi,

I'm currently reviewing a theme where the author is deregistering a  
WordPress bundled stylesheet "wp-mediaelement". This is being done  
within a custom theme class and immediately the authors own stylesheet  
is being registered.

Is there any problems with doing this? I know that deregistering some  
scripts such as jQuery are not allowed, so thought it best to ask.

Thanks,

Afzaal