IMO I would not be surprised if the frigate replacement was as big if not bigger than the AWD. As much as there was feedback that 7,000t is "too big" I think that is realistically, the small size. If 7,000t is too expensive, then the F-105 has a running head start.
I think the F-105 concept has merit, but depends how its done and how extensive. Best case scenario, you have a very cheap and near instantaneous build, with all the features and system we want, with great commonality. What you save on the hull you can throw into systems, sensors or missiles or what ever.
I guess its like anything, the devil is in the execution and the details. I think the F-125 is the benchmark, if we were deciding in a vacuum, and cost was irrelevant, it is probably the newest hull shape, ticks all the key boxes, two helos, ASW, 48 cells, flex deck, low crewing, high availability, newest systems out of the box.
Then again I think what could be achieved with an updated F-105. However, to fit things on our frigates I wouldn't be surprised if you had to lengthen it if your going to keep the same VLS and other features (which we would). I wonder if they can get the crewing down to that ~125 odd.
What we want is a F-105 evolved. Much like the F-125 evolved from the F-124. But will the hull basically the same (longer?) but everything else modern and improved.
Either way, RAN would look pretty formidable with either packing SM-6, Auspar, Tomahawk, etc.