Checking the status is really more of an infrastructure matter; it's nice that Hibernate Search can check it automatically, but some would say it's really none of its business. You wouldn't ask Hibernate ORM to check that your distributed postgresql database has all nodes up: it's postgresql's business.
It introduces problems, too: in development environments, or in single-node production environments,, you'll never get a "green" status. And that's fine: Hibernate Search will work perfectly even with indexes in "yellow" status. So with "green" as the default requirement, users discovering Hibernate Search with systematically encounter an error on their first startup, which is really bad UX.
Let's relax the default requirements, and ask for a "yellow" status by default. Users who really want to check for a "green" status can always add it later.