Sorry, but this is silly and uninformed and plain wrong.

The reason some instruments tune to different tunings is twofold - to more easily access chords and to change tonality. As a bassist, unless you're strumming chords - which can happen but is rarely heard done right in a full band context - your tuning doesn't matter. As for tonality - you're a bass, why do you want to tune your instrument 2 semitones HIGHER - wou're responsible for the low end.

Like everyone says, what matters are notes. If a song is in DADGAD or drop B, the notes you're playing are the exact same. The only thing that's different will be all the fingerings and shapes you know to play bass with will now be completely useless.

Look at the music see what is required of you. If it makes sense to switch your tuning, then do it. If not, there's only two questions you need to ask the band: "Did I play the right notes and lay down the correct groove?" and "Do I tell you how to play your instrument?"