Mac running 10.14.4
InDesign 14.0.2 working color space is sRGB
Image placed has embedded profile of sRGB
Native InDesign content created with color numbers matching those in image
Exported to ePub

Result: RGB color numbers of native object correctly match those of original sRGB numbers BUT those of the placed image have changed. The numbers indicate they have been converted to the active display ICC profile!
Happens whether object export options on image are set to JPEG or PNG.

I confirmed this by changing the monitor profile in System Preferences and relaunching InDesign. the exported image's color numbers changed to the color numbers of the new monitor profile.

Expected result: all RGB content should be converted to sRGB or, less optimally, all RGB color numbers could remain the same.