This fix can be demonstrated by the following:
b = bytearray(32)
f = framebuf.FrameBuffer(b, 32, 8, framebuf.MONO_HLSB)
f.pixel(0, 0, 1)
print('MONO_HLSB', hex(b[0]))
b = bytearray(32)
f = framebuf.FrameBuffer(b, 32, 8, framebuf.MONO_HMSB)
f.pixel(0, 0, 1)
print('MONO_HMSB', hex(b[0]))
Outcome:
MONO_HLSB 0x80
MONO_HMSB 0x1