Does 1.13 come with major mod-breaking code changes? If not, then we definitely won't settle on 1.12 and the cycle continues. If it does, then it's going to be a bit before things get caught back up. I think that's realistically the bigger factor than how cool the new content is.
Previously, I had the notion that it's better for the modding community to get into a good stopping point like 1.7, but the more I ponder on it, the more I realize that the "glory days" of 1.7 are never going to be topped. Infinity will never be dethroned. And... That's ok.
You can't recreate the past and expect to do better. The future of modded minecraft, IMO, is in custom packs and packs designed to hit specific notes. Variety. Different looks. Different goals. That's arguably better than a single monolithic experience in the long run, and the sooner people stop chasing the original king of modpacks the better. It's also OK to leave some stuff for Vanilla to be Vanilla. Vanilla is its own experience. It has its own goals, its own dangers, its own rewards.
There's more to a golden era than just the sum of its parts. 1.7 happened organically, and is preserved in that state forever. Some parts of what inspired that era was the emergence of all these mods that we now take for granted. There's no way to recapture that feeling with just new versions of the same mechanics. Now, the only way to create a new classic is to diverge from that norm. I think that's where we are now, and I think that's where we're heading.
