Good history lesson on the original beams...explains why our F18's are such pigs.
The top A-Cat in the world right now is arguably the DNA. It does not have a striker on the beam! When you go to a C-cat, AC45, AC72 etc. the loads are much higher than on the smaller boats, the structure is physically much larger and yes a triangle striker will be lighter.
I suspect there is enough weight budget in the F16 class rules that a carbon front beam can be made to work and this is more aerodynamic than the triangle beam, plus better from a wave slapping standpoint. This of course is more costly. That is why IMO the F16 class needs to tighten down the class rules and follow the F18 lead in some ways on this issue as you continue to build fleets-no one wants an all-carbon F16 class killer.
The A class has significantly lower loads than a 2 up spin rigged F16. It is also narrower so making a strikerless beam is a more reasonable solution to their design tradeoffs. The DNA chose this path and have a fast design. Would the boat be even faster or stiffer mounted with a striker?
There is a minimum weight for the class. They cannot go below this, so a lighter striker system does not buy any weight advantage as it does in the larger designs you mention. They chose a build process that used more carbon but fewer pieces and the sales pitch for lower windage etc. For this boat probably a wash both cost wise and performance wise.
There is a min weight for the F16 class as well. There are also already minimum or very nearly minimum weight platforms out there made from standard laminates. There are also various degrees of carbon to full carbon boats out there. The class is continuing to grow and the existence of these boats has in no way brought about the death of the class. Allowing options is an attraction for many. This doom and gloom prophesizing is getting a bit worn out. The DNA did not kill the A class nor did the Flyer or the first of the 75 kg generation like the Jav. All those boats seem to have increased participation not killed it. The F18 class has been very successful and I wish them continued success as it is good for multihulls, but the class is not for everyone. Just a quick view of the infighting and continued arguments over materials and rules minutia is more than enough to drive me from considering an F18, nevermind having to pay that kind of money for an overweight out of date vessel.