Placement schools are unlikely to offer you an NQT position
It’s true, sometimes a placement acts as an extended interview: you get to know the school, they get to know you, it’s a match made in heaven, they offer you a job and Bob’s your uncle. It does happen.
In reality, there are no guarantees and you should regard your placements as simply that. They are opportunities for you to practise your teaching. Generally schools don’t plan to offer positions to trainees, but act as trainee hosts year after year.
Even a placement is going swimmingly and the school does want to keep you on, it may not be in a position to do so or be unable to make a decision until later in the year. Keep your options open by looking for a job independently while you are on that placement.