I think Disney has already shown their hand with how they want to handle pricing of Genie +. If they wanted Universal Express Pass pricing they would have started G+ much higher. Disney has a lot of history now with the Fastpass and G+ system.
Keep in mind, Fastpass in it's original form was put in place because of the overwhelming complaints by guests in the 90's that lines were too long. All they had at the time was standby. To answer this, Disney introduced Fastpass to great guest satisfaction. Park attendance started to increase significantly as a result, and that continued and continued until Covid hit. There were suggestions pre-covid that it was becoming difficult for Disney to manage the amount of guests using the FP+ system since everyone had access and there is only so much ride queue capacity for it.
The more costly Disney makes G+, the less will purchase it, and if taken far enough it will drive the parks right back to "standby only" like the 90's when guests #1 complaint were lines. Disney wants more guests to be happy, not a few really happy guests. Hence, I think Disney wants a lot (but not all) guests to use the system so that their park experience is more enjoyable. To accomplish this they are keeping the price manageable. They are testing the waters of what guests will pay, but I don't think they ever intend to make it exclusive by jacking up the price anywhere near something like Express Pass. Also keep in mind that stays at WDW are commonly far longer than at Universal, and when you are staying a week per se, something like Express Pass just becomes ludicrously costly.
We did ONE trip with no FP or G+, summer '21, and vowed we would never return unless a system was put back in place. We stood in lines practically all day in the park, (that's no exaggeration) and had little time to shop, grab a snack, enjoy the atmoshpere, etc... We had to get up super early just to get ONE, maybe two headliners completed before the lines stayed very long for the rest of the day. That whole experience just wasn't fun, and night and day versus having FP, FP+, or G+.
Dan