You are currently offhore, right?
You've lodged your EOI which led to you being invited?
Was the invite requires you to have a JO? If you are applying for a different visa pathway and NOT the working visa (457), JO is not a requirements. Never was it a requirement to have a JO if they are to come in another visa aside from a 457. And from a working visa, that is, you are now onshore, then you can apply for another visa, PR then to citizenship.
You can proceed with your visa applications, if all are complete, and you satisfied the CO, then a visa will be issued, have a look at the link below;
In my case;
i was offshore (outside PH) and applied for a job based in QLD, got a positive response and from there, with my former employer's assistance, we applied for a working visa (457), family included, visa issued, flew by myself and landed in QLD mid 2008, family came early 2009, got our PR after 2 yrs, and citizenship at 4th year