I believe the parent was referring to [1], which blocked dual nationals of the aforementioned countries from using the visa waiver program if they were eligible

I believe the parent was referring to [1], which blocked dual nationals of the aforementioned countries from using the visa waiver program if they were eligible under a different nationality (e.g. a dual UK-Iranian national could not enter using the VWP on their UK passport). However it was an act of congress, not an executive order, though it was supported and signed by the former president. [1]: https://www.theguardian.com/us-news/2016/jan/15/iranian-americans-visa-regulations-waiver-programme-us-immigration https://www.theguardian.com/us-news/2016/jan/15/iranian-amer...