As long as you made sure the proper resistor value is installed in R4 it will probably be fine. If you haven’t already, put the rest of the parts together and test it. See if the D# key works alright….it should.
Resistors in parallel always equal a lower value that either of the original resistors. In this case there is some internal resistance on the micro controller pin that R4 is attached to acting in parallel to to R4…causing that point to be lower to ground than 750K. I don’t have a Macchiato in front of me at the moment to compare it to, but It should be fine.