Interesting. From the web page:

"This domainname, is DNSSEC signed with this algorithm."

Yet:

dana@araman:~$ whois ed25519.nl

Domain name: ed25519.nl

Status: active

Registrar: TransIP BV Schipholweg 9b 2316XB LEIDEN Netherlands

Abuse Contact:

DNSSEC: no

Domain nameservers: mango.plexis.eu pdns-public-ns1.powerdns.com pdns-public-ns2.powerdns.com

Record maintained by: NL Domain Registry

...

I'm inclined to believe the claims of the web site without checking. It's just interesting that:

1. The whois data for .nl is taking some interest in DNSSEC

2. That they are wrong about it being DNSSEC signed.

My (weak) guess is that whatever they are using to get the DNSSEC information doesn't understand Ed25519.