Not in the sense of recovering real detail. Upscaling with bilinear interpolation does not create new fine detail; it only interpolates between existing pixels. When you then downscale, two things happen: blur can appear reduced, but the smallest details are also averaged away or lost if they fall below pixel size.

That is why the FFT/power spectrum can look different after the upscale-then-downscale path: the resampling changes how frequencies are distributed, and if you were only rescaling geometrically, the spectrum width would increase accordingly. But because the upscaled image contains no new high-frequency information, the apparent improvement is mostly a resampling artifact, not true added sharpness.

So yes, the result may sometimes look a bit crisper, and the effect can show up more clearly in the spectrum, but it does not restore lost detail. In practice, downscaling often hides blur and noise, while also sacrificing the finest image information.