The main positive is that the World Cup is finally expanding to 24 teams in 2027. It'd be interesting to see what teams will end up qualifying in those 4 spots. A lot of the qualifying stuff depends on how many spots are allocated to each continent or whether they pursue a larger repechage going forth.
On playing form, there's a reasonable enough argument to give 2 spots each to Europe and the Americas. However, even without the whole qualification scenario being sorted, there are guaranteed a minimum of 4 changes to the composition of the tournament, which in my opinion freshens up the variety of the group stage. Sure, there'll probably be a few big scores here and there, however, it is vastly outweighed by the exposure the lower-ranked qualifiers get, along with any players getting professional contracts, etc.
The "Nations Cup" on the other hand is very unfair as to be expected. The same teams vs the same teams for a trophy every 2 years that can't rival the Webb Ellis anyway. Japan and Fiji will "host" games at neutral venues in order to cut down on traveling is just one of the issues.