I follow a few Disney nerd YouTube channels/Twitter accounts who love everything Disney, and even they didn't seem all that impressed or reserved in their reviews of Dumbo. Anecdotal and a small sample sure, but that's still some pretty damning evidence.
Runtimes w/out credits and attachments for next week:
Breakthrough: 1:52. Attachments unknown (probably Spies in Disguise and one other Disney movie - Aladdin?)
Penguins: 1:12. Attachments are Frozen 2 and Toy Story 4
The Curse of La Llorona: 1:28. Attachments unknown (likely Annabelle Comes Home and It: Chapter Two)
In all seriousness, this does have potential, but I could see a scenario where it has a strong initial interest in the first year, but there's a very strong chance of churn in year 2, especially if the originals don't deliver.
Now that puts the whole Fox situation interesting, since HBO has movie rights for new Fox movies up until 2022. Sound of Music and Avatar were shown, but how does something like Dark Phoenix fit into all this?