Cassie - a subject near and dear to my heart (...ummm, not you, Cassie but rather triathlon). I have completed a couple iron distance events, a dozen or so long course races and 60 or 80 Olympic and short course races. CrossFit is great for sprint and Olympic racing but does not help as much for long course and almost not at all for ultra course racing...at least that has been my experience.
A quote I like from Graham Obree's cycling coach "If you don't go 30, you won't go 30" applies just as well when you say "If you don't go long, you won't go long." I spent very little time going long this year and during a 100 plus mile race early in the season I suffered for it. It was a mountain bike, road bike, kayak, run race from Snoqualamie Pass to downtown Seattle and my high intensity training did not prepare my 51 year old body adequately for 11 1/2 hours of torture and torment. The half-marathon at the end was particularly crushing.
You should maintain your CrossFit training for sure and work in your tri training to the degree that you want to be successful there. Of course the more tri-specific training you do the better you will be at that. This is particularly true in swimming as there no crossover to speak of from other sports to swimming. The longer your race distance the more LSD time you need. If you are doing sprints the CrossFit matchup is perfect and it goes downhill the longer the race format.
It is difficult to be terribly specific here as much of this depends on how your body reacts to various training methods. For me I have to be pretty specific in order to peform adequately in triathlon.