Just for sake of clarity, I’d to point out that ARIN does provide basic registration services to all legacy resource holders without fee or agreement – these basic services include registry updates via ARIN Online, Whois/RDAP publication, reverse DNS services including DNSSEC, etc.

(Legacy resource holders who wish RPKI and/or authenticated IRR services are indeed required to enter an RSA agreement and pay service fees, just as any other customer.  For more details see here - https://www.arin.net/resources/guide/legacy/) 

Thanks! 

/John