For the Buddhist texts, how could they own the rights to works written hundreds of years ago? They're simply digitizing the work, no translation. Here's an example:
https://archive.org/details/bdrc-W1FPL194/page/n7
If the works, before their digitization, only existed in a private collection at a particular Buddhist temple, then their copyright clock wouldn't have kicked off. It would start the moment that the works entered the public sphere in some way. If that happened because of the digitization, then the digitization is under copyright. In this case, the original work is the "manuscript", and they're the "publisher."
Obviously at the time the texts were written, they were in circulation, but it predates modern copyright law. So maybe there's a loophole in the law they're exploiting, but regardless it's unethical, and Archive.org has the power to not accept works under those circumstances.