The main purpose of upsampling before digital to analog conversion is to move quantization noise far beyond the audible spectrum to be able to filter it out by simple second-order low pass analog filter. So dithering may be an overkill in this case.
dithering and noise shaping are techniques that are applicable to any operation that has quantization (a.k.a. "rounding")happening to the data. you dither and noiseshape in conjunction with rounding after an arithmetic operation.
dithering has the expense of generating a random number (or two) and massaging it to get the properties of dither that you want. noise shaping has the expense of a filter in the feedback path (the filter might be very simple, maybe even just a delay of one sample).
upsampling is done a few different ways, perhaps with polyphase filtering using a different set of FIR coefficients for each fractional delay (you would have 8 fractional delays if you are upsampling by 8x). this FIR multiply-accumulate operation is the same as a dot product. when the accumulation is done, you will likely need to quantize the word to be a shorter word going out. you might want to dither and noiseshape the word getting quantized. might not be necessary.