I have two bamboo cutting boards that have never been oiled and they are perfectly fine. I actually prefer bamboo over normal hardwood because they last so much better will no maintenance.
I use a butcher block mix with mineral oil and beeswax. The wood wants / needs it as it will dry out.
And honestly I always cut raw meat on a plastic board that I can throw in the dishwasher. These wooden cutting boards are for serving or cutting cooked food or chopping raw veggies.
I’m not debating the anti-bacterial qualities or getting into that debate at all - my focus was on knife sharpness and keeping them sharp.
If we want to debate bacteria, we could talk about handwashing, wearing gloves cutting raw chicken, sterilization of knives once you cut raw meat, etc. I prefer not to go there - too much to argue!