I sent an email to the archive asking about the new links and they replied that there is indeed no conversion scheme for old links. They also said that the new links are more permanent and are expected to stay the same if there is a follow-up of the current system.
The DTB books (baptisms,weddings,burials) will be scanned and made available later this year or next year. Also in the coming years more scans will be added, most notably the civil records.