Actually Ironhide was planned for Transformers prime but was scrapped. There's some artwork of Ironhide before he was scrapped, and the art work is from 2009, only a year before Prime's release.
Bumblebee: Can we go to Ponyville latter? Optimus Prime: No Bumblebee in Equestia... Pinkie Pie: Awww,i was looking forward for Team Prime's return,they left so soon last time. (watch team prime goes to Ponyville)
bee: wanna see my inpression of ironhide raf: mhmm bee: here it goes raf:mhmm bee: feel'in lucky punk?! im over here like: thats the best ironhide inpression XD
That honestly would make sense to me, but as emperor kumquat said, since they all have more fully functioning voice boxes, it might not be regular Cybertronian, but rather, a form of shorthand cybertronian code. To be honest I do prefer the theory that he’s actually speaking Cybertron in and the difference between his voice box and everyone else’s, is that Cybertron invoice boxes 10 to have a wider range of abilities and might have more intricate technology involved as well as bigger data packs, which would explain why they could so easily speak other languages fluently and for all we know they communicated in other languages before, although the biggest plot hole I think they somehow missed in the show is when agent Fowler was pretending to be a Deceptacon guarding a part of Deceptacon property and the Deceptacon answered speaking English, and saw nothing wrong with Fowler speaking English and assumed he was still just yet another Deceptacon.
Alright something makes me think that Bumblebee fell asleep and he started to dream about the decepticons destroying Ponyville and he wanted to protect the city or village and the Autobots tried to wake him up and then 24 hours later he woke up and the Autobots were Cybertronian Bronies and Bumblebee became friends with them. Lol.