Hotel pricing has definitely dropped off the highs back in 2022, parks are filled with lots of FL residents now taking advantage of 2-3 day $200 ticket deals.
I am very interested in seeing what happens when people start planning trips for Epic Universe and are met with a ~$300 3-day Universal ticket and a ~$600 WDW 4-day ticket (and that's without park hoppers and picking an average priced day).
Oh it's going to be a blood bath. The average person in 2025, before looking at pricing, is thinking about an Orlando trip in three different ways:
1) Standard WDW trip but with a day for EU
2) Universal Trip but with a day for WDW
3) Universal Trip
Regardless if that person is a WDW fan or not, EU is going to be on everyone's mind in 2025. Disney and Universal are going to bitterly fighting to get days from people and Uni has the upper hand.
Disney is going to have to fight to get as many #1s as possible. You are going to lose a lot of people to a single day at EU. That is the baseline attrition you need to fight for.
The problem for Disney is that Universal is going to play hard at making their resort a full week stay. In order to do that, they will have no issue to HIGHLY incentivize you for a multi day stay like you said. Buy 2 days at EU and get 2 days at UFL/IoA for steep discounts for example.
To prevent that from enticing too many people, Disney is going to have to do something to incentive at least more day trips to WDW from Universal to at least capture some losses. Disney has to fight hard for as many #1s as possible while being aggressive to save as many #2s from being #3s.
Ultimately we win in every scenario as a consumer.
edit:
Yes there will be plenty of people who are doing a WDW only trip and won't consider Universal at all. There is still a demo of families with very small children that Universal won't capture yet.