Yeah, some scientists consider it pseudoscience. It says in the second paragraph of the WebMD article that it is controversial.

Also from the article:

The U.S. Department of Veterans Affairs considers EMDR an especially effective treatment for people struggling with PTSD.

It is completely normal in science to „fight“ and have different opinions - so I don’t see any problems. Even if it was just (!) the Placebo effect helping a person with PTSD - why not try it?