Pretty sure they used Unity and not their own engine so it's not gonna require them to go that low level. The most they could do engine-wise is to update to a newer Unity version if they haven't.
Actually, you're right! What I meant was that it was harder to recode the entire thing, which is the route that they'll take for these updates. I got the wording mixed up, because English is not my main language. Sorry about that, will edit for clarity xD
