GPIO push/pull and pull-up resistor?
What your solution will do when the PIC is powered down depends on the pin type (some are 5V tolerant which means there is no diode to the power rail).

Looking at the absolute maximum ratings for 5V tolerant pins shows a maximum of 3.6V when Vdd &lt; 3.0. Whether this holds true when powered off is not specifically answered, but as it appears to be an electrostatic stress rating, I would suspect so.

For normal operation, the output voltage depends on load as you will see in the output driver specifications. Although the minimum output voltage that is guaranteed is 2.4V, the more likely output voltage will be far closer to Vdd for an interface to a high impedance input.

I notice that you pull up to 3.4V - is that because your module has true CMOS inputs? (transitions at 1/3 and 2/3 Vdd).

Edit: The dsPIC33EP absolute maximum rating for Vdd > 3.0V on a 5V tolerant pin is 5.5V, so I don't really see an issue if you don't exceed that.

Some current will flow into the line if the pullup exceeds Vout, so the the PIC output is high but lower than the pullup, then the pullup will tend to try and backfeed the pushpull output. Provided you do not turn on the body diode of the upper FET (a diode drop), I would not be particularly concerned.