Intermodulation always goes together with harmonic distortion. Whenever there is harmonic distortion, there’s also an intermodulation, as long as the signal contains more than one tone/pitch. True for both analog and digital.
Aliasing (i.e., intermodulation with the samplng rate) is a separate issue that only exists in digital. However in analog there can also be intermodulation with tones not belonging to the signal, like electric hum or tape bias.