Pull what is correct.
Many schools say there is a chance if and when a vacancy occurs, but bear in mind there always has been an abundance of restricted FIs. A restricted FI needs supervision and it can take time to gain the experience which can place additional pressures on a school trying to sell flight training as a product.
I don't want to put you off instructing, something I enjoy, but please be sure what your motivation is. If it is for a career in flight training then that is great and it will take time. If it is to purely to build hours for an airline position I think you would be well advised to save the money spent on an FI course (and living costs if employed) and put it towards training for a type rating.
Having stated the above, I have not seen a school that deliberately misleads people.