Is it possible this auto reject email was a mistake?

My husband has been interviewing for a corporate job we've been very excited about and there has been a lot of great signs he was going to get it. I'd love to hear what others think about what happene

My husband has been interviewing for a corporate job we've been very excited about and there has been a lot of great signs he was going to get it. I'd love to hear what others think about what happened. He had a phone screen back in November. Got a call back a few weeks later about wanting to move forward and they scheduled the interview with the hiring manager (who would be his direct leader). This was the first week of December. He had the interview and it went REALLY well. He told my husband he was very interested but that the next steps might not be until January. He ended up hearing a few days later they wanted to move forward and schedule two more separate interviews. They scheduled them and in the same day the recruiter from the company asked what days he would also be available the following week to do another interview in person where the hiring manager was going to fly out to meet in person. He had the next interview which ended up needing to be rescheduled for a different time (in the same day) which was fine. Interview went well and she even wanted to make sure he won't be traveling for the holidays. Then for the next interview it got pushed from Thursday to the next day which was Friday then on Friday morning he found out it's getting pushed to Monday. Saturday morning he got an auto email stating the position has been filled. But the interview is still on the calendar for Monday. The calendar invite hasn't been cancelled. We aren't sure if the auto email was a mistake or what? It's really disappointing because everything has seemed very promising, even things that were said in the interviews made it seem like they were set on hiring him. The recruiter from the company would text him right after the interviews asking how they went. I know we will find out for sure tomorrow but I can't help but remain hopeful that it was a mistake. My husband is pretty sure it's cancelled. He's sweet and still telling me it's possible.