The URL to the ARIN TAL nor the ARIN TAL document itself is not copyrightable. The ARIN TAL document contains a URL and a key, which is a machine generated random number. Neither is based on any creative work whatsoever, and so can not be copyrighted. Also would be protected by free speech and fair use.
The service itself can have terms and conditions, but access the the TAL document is not an effective enforcement. Bundlers of software can include this information at will. No need to download it.
I understand the issue is that ARIN wants protection from being sued, should I somehow harm myself with this service. However ARIN already offers a similar service without any terms and conditions: The reverse DNS. As reverse DNS is often used by SMTP mail servers and mail clients to stop spam, I might not receive an important mail due to the failure of the ARIN reverse DNS service. And then sue ARIN for my financial loss.
As a compromise, I suggest that ARIN outsource the service to somewhere with a less hostile legal environment. For example, maybe RIPE could mirror the ARIN service. The ARIN service may still require terms and conditions, while automatically installed software would use the RIPE mirror.