I'm going to go out on a limb here and state that it has something to do with the TF religion. With the recent reveal of the "Mistress of Flame" (which pretty much acknowledges that genders do exist) , an explanation could be that the followers of Solus Prime (thanks Aligned continuity -.-) purposely modified their CNA to what they believe is a homage to Solus by some ritual. Prior to having the aligned continuity being shoved down our throat, you can see that every discussion of religion in the comics centered around the guiding hand. Dai Atlas, Star Saber, The Functionisits, Cyclonus all have a certain view about the TF Mythos. It may very well be that with the expulsion of the primes, various sects or offshoots of the same religion fled/died and the ones who were left propagated the dominant narrative which is why the bots that currently exist in the IDWverse can unconsciously identify the changes to the "CNA" and thus use different terms for Wingblade/Arcee etc and different terms for Sludge/Rodimus etc. However since they haven't been taught otherwise and the knowledge is so far gone (information creep ba-dum-tss), they believe cybertronians have no gender However the reason why i think this discussion is a little flawed is because the writers of the IDWverse keep changing their stance on the issue. I remember reading an earlier thread where people had mentioned seeing billboards of cybertronians who did look female in nature and spotlight Bluur also had a few of them. My point is the reason why the transformers had genders, then didn't have genders and now have genders again is simply because the various writers all had different stances on this issue =p.