This is how a subscription model works, you hook them for one thing and get them to stay for all the rest including new stuff that comes along. As long as there is enough to keep the subs without much churn (which Disney has one of the highest retention rates, something like ~95% second only to Netflix at ~97%) that is all that matters in the long run, as this is feed by all the Studios which would be producing the same content anyways.
I think what some are confused about is thinking it needs to be "new" money for every transaction, as in there mind its only "new" money that seems "real" because that feels tangible and real. Its an argument that was often seen back when D+ initially released as the reason why streaming wouldn't work and the service would fold, and yet we're here 5 years later and its working. That is the old model of thinking with theatrical, because you only care about the new money coming in for a specific movie in that model. But in a subscription model you care about the money coming for the entire service, as long as that money coming in makes more than the content spend for the service that is profit. Its a different way to get to the same end result, ie overall profit for The Walt Disney Company.
The only people really that should be caring about what specific content does on the service, ie how many views it gets, is those that care about their residuals, and maybe Disney for the ad dollars. As now with the new contracts after the strikes the actors and writers once again get residuals based on that content, and in many cases have written in performance bonuses based on how it does on the service.
Disney already had one of the longest release windows of all of Hollywood, averaging 90-120 days for their blockbusters, and at least 45 days for their smaller releases, so this strategy hasn't changed all that much other than during the early days of the pandemic, ie its not getting longer its remained the same for a few years now. While other studios have smaller release windows, and they do just fine, for example Uni's is 17 to 31 days on average.
Subscription models have been around for hundreds of years and used by many industries for a reason, because they work. Hollywood is just the latest to use it, and its clear its not going away.