As I understand it, Astraeus offer a type rating on a commercial basis, exactly as your FTO offered you an ATPL course. As your FTO, presumably, didn't offer or guarantee you employment at the end of their course, why should Astraeus? You are, after all, only contracting for a period of training on the B737, at the end of which you will have the B737 on your licence and you will, you hope, be more employable by the various airlines that use that aircraft.
I don't believe that this scheme bears any relationship to the Ryanair or easyJet schemes which are directly aimed at recruiting employees (at the potential employees' own expense), notwithstanding the fact that Astraeus have occasionally employed some of their strongest students.
Scroggs