Bally's Interactive Java Developer interview questions

HR screening call, zoom technical interview where they asked general questions about core Java/my CV experience and then in person interview where they asked a systems design question, code review and behavioural questions. process was fine, team were friendly and the interviews were done quite efficiently. HOWEVER, received an offer and then was told the following day that actually the business are no longer funding this sector and are disbanding the team so they have to rescind the offer. Surely this was something they would know in the lead up to the interviews? Surely this would be something that should have been mentioned in any of the stages prior to actually giving an offer? How did it get to the point where they literally sent out an official offer letter and it was accepted (and I had cancelled my other interviews) and then they actually decide they can't offer anymore? Grateful that at least this happened before I started rather than being 2 weeks in and being told actually we can't fund you anymore.