Well they have orders out to 2023 so hopefully they don't muck it up again. The airforce has done pretty well with its Orion replacements. They will not only get 15 P8A and 6 or 7 Tritons but they also get to replace the EP-3 with at least 4 Gulfstream G550s as well.
On a side note I wonder what they intend doing with the old Orions.
It's one thing having orders out to 2023, it's another thing to ensure that all the
long lead items are still being produced, that is where the real crunch time comes into play, assuming an airframe is delivered in X year, a lot of the parts would have been produced well before that date.
In regard to the USN EP-3s (and the two RAAF ELINT AP-3C (EW) airframes), its been reported that the MQ-4C is actually going to be fitted with a EP-3 'type' capability, it would appear that Triton will possibly be more of a direct replacement for those airframes, not necessarily the MC-55As (G550s).
What the actual role/capability of the four MC-55As will be is still very foggy and misty (certainly for most of us on the outside), I would imagine that they and Triton will probably have 'overlapping' capabilities to a certain degree.
As to what has happened to the old AP-3C airframes, two are still in service for a few years yet (the AP-3C (EW) airframes), the rest have either been scrapped, ended up as museum pieces and a fair number of them have been sold to a firm in the USA to be parted out, see the ADF-Serials link below:
ADF Serials - Orion
Cheers,