Can you please quote the things in the EO you fear could be used to tie gender roles to sex? It's not how I read it but prepared to have my mind changed.
If your fear is more general along the lines of "having people's sex recognised legally could be used to oppress based on sex as well as support based on sex" well yes, that's kind of unavoidable.
You could even conceivably say that the only reason feminists need to care about sex is because sexists care about sex (1). Feminism ultimately only exists because of an injustice that I'm sure we'd all rather not face in the first place.
But, as long as the sexists do care about sex, we also need to be able to define people by their sex and at times support them in ways specific to their sex.
(1) Simplistic take of course, because even if sexism itself goes away it will be a very long time, if ever, before society manages to design itself in a way that women don't carry an extra burden and financial risk due to our reproductive role and therefore need sex specific rights and supports.