The universe is expected to have gone through different phases, or epochs, during it history. I am not sure this is what you want to talk about.
For instance, we have the so-called electroweak phase transition corresponding to the restoration of the electroweak symmetry (strictly speaking, this is a cross-over in the Standard Model but not necessarily in its extensions). On each side of the transition, the laws of nature are different (here, the particles are massless prior to the transition).
So not, this is not speculation, but expected! :)
Thanks, I dont have a highly defined expectation of what the phases were, but certainly if the laws of nature changed then that is consistent with what I was talking about.
Let me try to empahsise my example. Who knows, it may help ;)
In the Standard Model, the masses of the particles arise from the Higgs field. This field has the particularity that it cannot be turned off (today), so that particles are massive no matter what.
In the early universe, there is a moment at which the Higgs field is actually turned. All the particle dynamics was different at that time (massive objects vs. massless ones).