Well that sucks. Can confirm; I get a page asking me to turn off my adblocker, and the HTML is just some "lander" page and JS junk

Maybe don't link it, then?

Not a hijack - the domain expired. It's showing a parking page from the registrar.

whois Domain Status: autoRenewPeriod https://icann.org/epp#autoRenewPeriod

Yes, it expired, see "Registry Expiry Date":

$ whois haiku-os.org

Domain Name: haiku-os.org

Registrar WHOIS Server: whois.namecheap.com

Registrar URL: http://www.namecheap.com

Updated Date: 2024-10-29T01:11:33Z

Creation Date: 2002-10-29T01:01:16Z

Registry Expiry Date: 2025-10-29T01:01:16Z

Maybe this domain will be renewed after all?

For the second year running, someone forgot to renew the domain. Surely they are aware of calendar reminders?

omg abandoned site