Why they put P.J. Soles in the new movie?

I didn't know they did! Probably because she has aged enough that casual fans wouldn't notice her... I know I would though!

So they could send her your way?

As long as it's a different character, I don't mind. If they brought her back for a scene as Lynda, then there would be a problem since Lynda died. Also, a lot of movie series/franchises do this all the time. They'll bring an actor back for a quick appearance but be different characters even if the new movie they'll be showing up in is a continuation of the same timeline their original character is part of and their character possibly died in. Just look at Ghostbusters 2016. The guys from the original two movies made appearances in the 2016 movie (well, 2-3 of them), but were completely different characters. Wasn't all that confusing. Also, Halloween is the only movie I have seen P.J. in, unless she popped up in other movies and I didn't realize it. And I may have seen her in interviews when doing some kind of special milestone anniversary thing for the movie, but I haven't seen what she looks like in the present. So I probably wouldn't have realized it was her or recognized her when watching Halloween 2018. I'll probably forget all about her having an appearance when I watch the movie.

was she the one closing the blinds when Mikey sneaks up behind her??