But I think that element should be able to contact element B anyway.
Well, with respect, why did you ask us if you've already chosen your answer? To me the wording of the rule is quite clear: elements in close combat block access to other elements.
I still think it's a geometric ploy because the player could choose the appropriate angle for element B not not be contacted on front nor flank.
No, I think that claim doesn't work for a few reasons. Firstly, the situation could easily arise through no conscious action of your opponent: Element B could well have been there unmoving for several bounds, and Element A could well have been recoiled several times. Secondly, if Element 2 had another element with it, you could simply advance and force Element B to conform. Thirdly, even if your opponent
did move Element B to that position, it blocks Element A's recoil - if you recoil Element A again, it will take a -1 in combat after that.