100% of my bass playing experience comes from rocksmith (only ever played guitar hero before, never a real guitar) and this is what I've found too, it just depends on the song and what sounds best to you, and you might not know until you play through once or twice. Some songs will play "picked" or "fingered" but I've found that's that's more of just a recommendation imo.
Side note, but if you're new at playing bass on rocksmith you might want to decrease the track audio volume to about 20% less than your bass input volume - it will make it a lot easier to tell what is you playing vs whats just part of the song, since I've noticed a lot of CDLC keeps the bass tracks fairly quiet