Hey,
I was wondering if I use a wp theme for a client site do I have the right to replace the preview image (under appearance) as well as author details, theme name etc… To match my companies branding just makes it seem more professional from my point of view.
Thanks!
Morally it is questionable but yes license wise you can do this.
I would still be VERY weary of doing this unless you are making noticeable changes or that the client knows it is a template theme, as it will look much much worse if they are led to believe otherwise and find out.
Most of the clients i work with aren’t tech savvy and keeping the descriptions and preview image as the original isn’t a problem I just feel if they did venture there would be nice to have my own log and website link instead of sending them to a web store.
As long as you are being honest with the clients then you won’t be taking any risks.
You can imagine less tech clients i.e. who don’t get what is involved in updating and editing themes; are going to be very curious if they see something very similar to their website for $50.
Either way it’s your choice and there is nothing stopping you updating the info and images .
I’ve had a client contact the original theme author before which was… well it was weird. The client was aware of the fact it was a template(due to their budget) and just presumed the link was to my website. 
I would change the details to avoid any confusions.Just don’t change any of the stuff that they don’t see just in case you forget what theme you installed. 
Hi I would like to reuse a license that I bought for the x theme on a new site how do I revoke the licence on my old site? please help. If this is not the right place to pose this, please remove.
there is no license to revoke, just stop using the theme on the old site and use on the new one.
Thank you @Garett_Gillman, will do.