Should I get my male rabbit neutered?

I would advise against getting the male. Anytime a 3rd rabbit is introduced to an existing pair, there is a very real possibility that it will break the bond of the original pair. You may end up with either just one female getting along with the male (which would leave one female alone), or you may end up with all three rabbits refusing to get along.

If you are ok with any of those scenarios, that's your decision. The male would absolutely have to be neutered and then wait 8 weeks post-neuter before introducing. If he's not fixed, he may harass the females to no end.

But introducing that male - at the risk of breaking the bond of your current pair - wouldn't seem like the best choice.

If you plan to bond all three you should definitely get your male neutered. When he reaches sexual maturity he will still try to mate with your females even though they are spayed.

It's not necessary, but he might be more destructive and spray if he isn't fixed!