You don't have to make a big decision right away, but those are certainly signals that the decision may be made for you in the next few months if you are unluck

You don't have to make a big decision right away, but those are certainly signals that the decision may be made for you in the next few months if you are unlucky. I'd certainly start the usual job-hunting process: updating my CV, mentioning to friends that I may be open to a new position, breaking out the ol' whiteboard for algorithm interview practice, going to meetups etc. Also, prepare yourself for being laid-off, financially and mentally. It sucks, but it's the reality of startup life. Don't worry about questioning the founders - it's their job to be upbeat and optimistic to get the best result for their startup, but it's your responsibility to look after your career. But that doesn't necessarily mean giving up the day job - hope for the best, prepare for the worst.