Tbh, I think (and hope) the new loot system can actually be beneficial to Siege´s PvP. Like Agra-Lem said:
As it is now, the few spots that offer good gear drops are hot spots for PKs.
With the new Global loot system more PvMers and merchants get a better shot at farming more and better gear which (again I hope) will lead to more vendors selling good gear parts for a decent price.
So if a PvPer loses his gear he can just go and spend 200-300K on 6 pieces and some jewelry to get his LRC, LMC, resists, stat boosts, regens, FC, etc and won´t have to spend any time farming it.
Time will tell but I actually think the new loot system can work for the PvPers if done right by the farmers/merchants.
Honestly, while im glad its going global (and op's notion that global loot was that goon, black rain's idea is nonsense, its was EVERYONE'S idea) because its just nice to not have to be tied to a few small areas, I don't think the loot change will do much other than make pks have to run around more to find marks.
Shame style loot is just too scattered 99% of the time in a game that basically requires that you have certain stats on your stuff. Really it's just caster jewelry/shields. A usable melee weapon is basically unheard of, usable melee jewels also super super rare and while armor can sometimes be usable, it's often just not as good as specifically imbued suits. Itemization in this game is just kinda borked IMO.
I do hear tell that one property stuff is dropping more often, and if thats the case, then this WILL be a good thing for us. Getting ssi jewelry and no other mods alone would be a real blessing for warriors.
The trader quests will only have an impact on the seas (but at least that's a positive), as every non fence quest will be run via moongate and people probably will rarely be leaving the GZ. It WILL be easier to fund towns though, which will be nice.
And since I highly doubt VvV will even come out in this pass, I doubt the publish will change life for siege all that much.
As for pvp... insurance is not the answer as was already pointed out. It just creates power inflation, and needing those fringe improvement uber gear bits (camping navery for weeks on end trying to get a slither etc) would probably be much more annoying than losing your stuff and having to imbue a new suit. I for one would close my account on day one, and that would be it for me. Insurance was why I left regular shards, and is the cause of many of the over all problems this game is currently facing, like content that requires 100 years to grind out for example. That artificial slowing is in the game because of irreversible power creep. They can't let you advance quickly because then they would need more content.
I DO think that more avenues of non gear loss pvp other than the areas would be a great thing for them to focus on.
Speaking of content, to the OP's point I agree. I too tend to get a wild hair about UO and get fired up to play only to fizzle out within a month because there's just nothing to do. New stuff is either a boss I can't fight with generally useless drops I don't care about, or a grind I usually don't have a ton of interest in. They have been really quite bad about adding new quality content for years now. Sadly I cannot see that ever changing at this point. Large areas specifically designed for pvp encounters with no loot rules would be great, and I think many non regular pvpers would get into them, sort of how champ spawns were initially operated.
Really this game, and more specifically this shard are just kind of fubar. For siege to run optimally we really would need our own designer who can set drop rates (which should be MUCH higher for rare stuff), and fend off tram changes from creeping onto our server. It's still the best UO going, but it could be SO much better with just a few tweaks.