This same rumor was running around USNA circles a month or so ago. In fact, it was not true. What is true is that the USN/USMC has much less patience for those who fail a follow-on school. In the past, if you didn't pass your tests at flight school, you'd be allowed to do something else, like SWO. Now, they are likely to separate you for even a single failure.
So, yes, you are out of your service obligation. You are also out of a job.
The Supe said that mids are being warned/counseled that they need to focus on TBS, flight school, etc. as failure may well lead to involuntary separation.