to my knowledge, mojang did alter the terrain generation algorithm throughout the years. not saying itll drastically change the terrain, but we may notice some straight edges where claims get pasted back in. nothing a little work and a few stacks of dirt and stone cant fix I think. as for the roads, I feel like some of them could be re-done.  as in, id like to see them re-done to be more smooth and more well kept. theres creeper holes all over the place, and a lot of areas could desperately use some refreshed terrain. I am willing to offer my time and resources to helping rebuild some of the path ways that will be lost, as well as helping to smooth out any terrain edges that don’t quite match up. even though it will be the same seed, opening a world with a seed from 1.5 will change if you opening it in later versions. I think YT user AntVenom made a video on this. he used a seed generated from an earlier version, and recorded how much the land changed when he opened worlds of the same seeds in different updates. the general layout stayed the same. biomes mostly were the same, only real changes were some terrain generation. it smoothed out a little here and there.

TL;DR: ill help fix whatever shit happens to break.