No. Not at all. I think the Brit infantry will remain with different sections for quite some time. See this
article. Personally, I think it is impossible to reconcile the section size as various platforms are built with varying limitations on internal space and crew functions. What works for a Wolfhound won't work for a CV 90 and what works for a CV 90 won't work for a Bradley and light infantry is another story altogether. I think the search for a common infantry section and its carrier is a hunt for a chimera.
The way that I see it that train has left the station. Ajax/Ares is replacing Scimitar/Spartan (Scimitars are now out of service and the Spartans were retired several years back - but finding their way to Ukraine). Note that Spartans also carried a crew of three and had only four dismounts and were basically designed to carry specialist troops to accompany recce. There was an entire family of the CVR(T) that was primarily designed for armoured recce operations. It strikes me that the entire AJAX family has exactly that same role.
Warrior, on the other hand, is being replaced by Boxer. The Warriors will all be out of service in the next year or so and it wouldn't surprise me if they made their way to Ukraine as well. The Boxers should have replaced them by then so there is no need (or money) to buy additional Ares for the armoured infantry. Besides, I don't think that they have the dismount capacity of the Boxer, but don't know that for sure.
I do like the 40mm CTAS concept. I also like Moog reconfigurable turrets (I'd like to see them on all of our LAV IFVs and AD and ATk carriers). The Moog turret does not currently have an option for the CTAS but it does not seem impossible as CTAS touts its customizability. Honestly, I know it sounds ass backward, but I would first find the IFV with the best weapon system and protection system configuration and design my section size and tactics around that. If the overall platoon size is too small due to limited dismounts then add a fourth section and a fifth vehicle. I actually think we already did that once with the LAV which was a dramatic change from the section configuration in our M113s days.