My biggest problems with the Pacific Cup as things stand are:
1, a team out every year which undermines its ability to have a coherent narrative with the average fans and impacts its viability. Samoa out this year deprives the cup of at least 2 big blockbuster crowds to give England a leg-up. England obviously needs a leg-up, so I'll come back to this point later. Australia out next year. If they win on Sunday, they won't be defending their crown. If they by some miracle got relegated, they wouldn't have to face the consequences. So its all a bit meaningless while we're chopping and changing top teams every year.
2, the 3 team format with byes. They could at least have cross-pool standalone tests to paper over it but it is just a dud format. At least we have a final unlike the 2019 Oceania Cup edition. Kangaroos not playing last week basically killed off any interest in the Australian papers despite a tantalising NZ v Tonga matchup. 4 Nations is the only worthwhile format that you can play in a month. 5 nations is a dud format, takes too long, still has byes.
On Promotion and Relegation. I like it. Stakes are important, and giving all playing nations a shot is important. I don't think the organisers will like it if we lose NZ to relegation next year. But then again, NZ are probably the worst drawing team of Australia, Samoa, Tonga, NZ so... tough shit? They were complacent despite injury outages. And I suspect some of those outages could have dug a bit deeper if they cared.
Having the tournament split into 2 tiers does a lot to manage the financial viability and public interest. Kangaroos v 5th and 6th placed teams over a 6 week period is not something the NRL is interested in bankrolling. The Bowl being cheaper to run allows for more games in places like Suva. And crucially gives every WC-eligible nation a fair shot at the big time, which the other Rugby does not.
My preference is to maintain and expand the current format, with no one out touring England and the top teams appearing every edition. But it seems like the current strategy will persist until at least 2030 where 1 Pacific team goes to England each year. So in that case I would have the tournament played annually with (examples as per mooted 2027 plans):
England series - 1 Pacific team (NZ).
Cup - Top 4 teams (Aus, Samoa, Tonga, PNG).
Bowl - remaining 1-2 pacific teams (Fiji, Cook Islands)+ Lebanon. + future expansion to include best Americas team.
Promotion playoff remains between Cup and Bowl.
On World Cup cycles... my suggestion has long been (Kangaroos events only for this illustration):
Year 1 - Pacific cup. No tours.
Year 2 - IRL 4 Nations featuring England.
Year 3 - England/GB tours alternating between the big 3.
But even so I can see it feels a bit spread thin and there's a certain appeal to playing the same events every year. As mentioned, looks like the NRL is going to favour an annual Pacific Cup with 1 nation ducking off to England each year. And despite the flaws i noted, it works. And should the NRL cut its rounds down with expansion, we could eventually see room for something akin to a short-form of the Union calendar, where we have every year.
1 mid-season test.
A touring window in October.
and an annual Pacific Cup in November.
In such a calendar the Kangaroos could play 8-9 games a year, and we wouldn't have the compromises of tours overlapping tournaments or only getting tours or tournaments in certain years.
And finally, on England...
It is frustrating that they are reliant on southern hemisphere teams as their only viable opposition. They could have France competitive within 5 years and Wales in 10, and have simply chosen not to support their neighbours. They have invented a criteria for Super League that could plant Toulouse permanently in first grade and decided instead to favour the status quo.
You can argue that it is not their responsibility, but what of their responsibility to themselves, to be able to sell the sport via internationals? They obviously recognise the problem because they are desperate for incoming tours. If the NRL decides at any moment that an annual Samoa v Tonga game is worth more than shipping them up to Wigan, England are left with nothing. And would hypocritically cry about Southern Hemisphere neglect of the International game while they revive rubbish like War of the Roses and leave France in the lurch. As always, they reap what they sew, but it's never their fault.