There’s no question that the name is manipulative since it was first coined to refer to what’s now called “coordinated disclosure”[0], in an essay which referred to full disclosure as “information anarchy”[1].
In this case with HackerOne, the issue is not with terminology, nor is it with time-gated full disclosure versus immediate full disclosure. Rather, the issue is that HackerOne go out of their way to serve the interests of vendors who don’t want to fix defects quickly, at the expense of reporters, end users, and software security in general.
HackerOne could take the approach of saying “we are a neutral platform for connecting researchers and vendors, it is not within our purview to try to stop reporters from disclosing vulnerabilities if they feel it’s necessary”, but this is not how they operate today, and people should know this.
[0] https://en.wikipedia.org/wiki/Full_disclosure_(computer_secu...
[1] https://web.archive.org/web/20011109045330/http://www.micros...