Reclassify changes pixel count

[LawlorBridget]

I am using ArcGIS Pro 2.8.3.  I have a raster with just 2 values: 1 and 2.  There are 93,878,957 pixels of value 1 and 106,250,349 pixels of value 2.  When I run the reclassify geoprocessing tool to convert value 1 to 0 and value 2 to 1, I end up with 120,808,871 pixels of value 0 and 158,563,049 pixels of value 1.  Why does my pixel count change?

I have set the environments for snap, mask, projection and cell size to my input raster.  (I also ran reclassify with no environments set, but the pixel count still changed.)  The raster properties of both my input and output layers match in terms of cell size, extent, number of rows and columns.  

Source raster:

Output after reclassify:

Does anyone know why the pixel counts change after running reclassify?  Thank you

[DavidPike · Accepted solution]

I might rebuild the raster attribute table and calculate statistics on the original just to check.

[LawlorBridget]

Thank you David.  That worked and my source raster now has the same number of pixels in the attribute table as my reclassify raster.