PIC outputs while programming
In the datasheet for your microcontroller there are four tables, table 2-1 to 2-4, which describes all the registers, including PORTx and TRISx.

The tables have a column named Value on POR/BOR Reset and Value on all other Resets which describes the register state at startup and after resets.

As you can see for TRISA up to and including TRISD, the state is 1111 1111, which means that the pins are configured as inputs, or in other words, put the corresponding output driver in a High-impedance mode.

Unless I'm completely mistaken, the programming mode should not change this, except for the pins relevant to programming.