I will tell an anonymous person to do this, but I’m not sure if Troy Hunt cares about a random one-of-thousands service and a few thousand affected users.
A few minutes ago, you were calling it a "pretty extreme data leak" and "millions of dollars" so I think he'd at least know how to validate the leak and enter it into HIBP.
These statements stand unchanged. The usage of "pretty extreme" could be regarding the "quality" of data, not quantity. Compared to the usual data leaks on HIBP it seems like an occurrence that happens frequently and the affected user count is abysmally low. Some anonymous person might fire off an email to Troy Hunt regardless.