No, it does not mean that the freelancer has read the job description and wants to be hired.
The "Hire" button appears next to the name of any freelancer you send a private invite to.
If you click the "Hire" button, it will send a direct hire offer to the freelancer, who will still be able to decide whether or not to accept the job offer.
"Invite" = invite a freelancer to apply for a job. If they agree they have applied for the contract and you can read their application to decide if you want to take things further.
"hire freelancer" = offer the freelancer a contract. If they agree then you have hired them. The job is confirmed.
The "hire freelancer" button is a firm proposal to work with the freelancer, whereas the "invite" is a request for the freelancer to tell you if they want the job and why you should hire them.
Thanks for reaching out to us. I checked but was unable to replicate the issue. Could you please check and make sure you are logged in on your Client's account and try searching for Freelancers? Alternatively, try clearing your cache and cookies or using a different browser. Let us know if the problem persists so that we can assist you further.