I really doubt it, for several reasons. The Neo is cheap because it mainly leverages a compute core that already existed, consisting mainly of binned parts.

Yes the chassis had to be designed, but that can be used in common for future iterations. That's much harder for phones where the chassis is very tightly coupled to the specific circuit board design.

The 17e already is the cheap iPhone and it's $599. Putting it's internals in a different shell is one thing. Designing and building a half price internal board is quite another, especially as it would either require an entirely new SOC, or mean continuing production of a legacy SOC thus taking up valuable die production pipeline capacity.

Even if they did use an older SOC. Now they'd have to continue supporting that anaemic underpowered SOC with OS updates for years to come, and these future OS updates would have to run well on it.

I don't see it happening.