Most likely it will be minor, but imagine if it was used as a convenient way to explain why Godzilla looks different (Dougherty confirmed he will be redesigned, though it's unknown to what extent) this time around? Like, they invent this new weapon and kill the Godzilla from the 2014 film, and then a new one appears and becomes
the Godzilla in the movies going forward. Would be very Showa-esque indeed.
Not that I think that's likely (especially since it would just make things even more complicated when they already have three new monsters to introduce), just throwing it out as an idea because speculating and coming up with wild theories is all we can do at the moment.