Now admittedly this is a bit more of a re-imagining and flight of fancy. Orvr in this context meaning the entire world, not lakes vs the rest of content as we talk about it in RoR terms.
The game is constrained by a small team of devs and the tools they have available to them to create new content\amend existing content i.e. they don't have an easy way to change what is already there. We know that outside the rvr lakes is a huge amount of pve content but generally holding trash item rewards the vast majority don't need or want.
I started on Eltharion, perhaps the server i had most fun on as it was an orvr server, not core and you could say that war was every where. i.e.you were always flagged for a fight where ever you were. Some of the best fights i had were in and around pq's etc and despite what you may think it wasn't a lowbie gank fest and tended to be self-policing and brought a different dynamic to the game instead of just fight in the same lakes over and over again, following a pretty set pattern.
I would argue that when mythic brought out the game it had its orvr/core/rp servers, the core servers appealing to the wow pve crowd, but RoR is very much a pvp crowd not that bothered with pve, so why restrict its ruleset to that market anymore ?
The issue is of course why would anyone do a PQ these days, they don't, you just get trash gear but what if the PQ's actually gave some thing you wanted or actually needed. Could the PQ's be designed to drop something that is wanted or perhaps items that could help the overall campaign, maybe high end armour potions, lizard scales, aversion pots etc. Would this spread the battle out if the orvr rule set implemented by default and the battle spread out from the lakes? This wouldn't need the devs to try and shift map boundaries and move bo's just allow you to fight in a greater area. Fight in Death Peak,West Praag or that amazing temple above the Order warcamp in Chaos Wastes, travel see the world, fight and they will come

Or if your guild needs resources from the farming areas, be prepared to come and fight for them, you can fight the opposition while you are farming lizard scales. Nothing like a bit of restriction in guild supply or personal gold to motivate people. You never know it might not be just guilds that fight for resources but ad-hoc mercenary farmer groups that band together., alla EVE style. Obviously restriction in supply = More expensive items in AH = less people able to buy = less effective realm fighting force overall. This brings an economic element more into the game and outside "getting stuff", control of resources one of the biggest reasons to fight and a different game dynamic. What happens when people don't have access to their high end armour or aversion pots? Waiting for the economists among us to chime in. Edit: In retrospect, maybe a really stupid idea as we end up with WoW type gold farmers and pay to win but will leave it here any way

It MIGHT make it more of a sandbox type experience instead of the on rails system we have currently and Eltharion always felt more of a sandbox than the servers that came after it, which felt a bit tame\lame by comparison.
So
1. I would exclude T1 maybe T2, you don't want lowbies getting ganked
2. orvr rule set instead of core. Ror already implements 1/2 of this already i.e. you can traverse T2-T4 tiers without turning into a chicken, just flag everyone as in combat in the pve zone content as well. Only safe harbours are the War Camps and your City when not under siege.
3. Something that brings PQ's back into the game and turns them into battle areas worth competing for.
You may think these are daft ideas and will have downsides i'm sure but thought worthwhile to just chuck them out there as you never know it might spark someone to have other ideas.