No you are right but I believe if you use a high resolution for this temporal reconstruction it will decrease the number of artifacts because you need to reconstruct less.
I suppose that depends on what your final resolution is.
If you are still trying to target a final resolution 3 or 4 times higher than you base, then you still have a lot data to fill in.
To reduce the type of artifacts that quantum break has you need to use less frames. So using a higher base resolution and finishing with the same 1080p end resolution would be one way.
Id like to think that with 4.5x the grunt, then could get to get to at least 1800c resolution, thats less demanding than native 1440p but would potentially net a better result, especially given the CG look they were going for.