I agree with David.
There was a time where m expressions and such were being toyed with but for me it's still about s-expressions.
We're already on a slippery slope losing Lisp identity to the other dynamic language's syntactic sugar.
Here and no further I say.
Sorry I'm late. I haven't programmed in Dylan myself, but I believe that it should be considered lisp.
1. It is from the moon
2. KMP's wonderful More Than Just Words on why Dylan is welcome at the european lisp symposium https://www.nhplace.com/kent/PS/Lambda.html