Repository: next.js
Issue: removal of apple-mobile-web-app-capable results in splash screens not working
Labels: Metadata

### Link to the code that reproduces this issue

https://github.com/jwanner83/next-apple-web-app-issue

### To Reproduce

1. Checkout this repo https://github.com/jwanner83/next-apple-web-app-issue

### Working example with workaround

https://github.com/user-attachments/assets/a12c17f3-c8de-4b36-ab71-b4429626bb03

In this example, I am adding the required meta tag in the root layout through html: https://github.com/jwanner83/next-apple-web-app-issue/blob/main/working-with-workaround/app/layout.tsx#L167

2. Go to [working-with-workaround](https://github.com/jwanner83/next-apple-web-app-issue/tree/main/working-with-workaround)
3. `pnpm i`
4. `pnpm dev`
5. Visit the page with an iPhone and add the page to the home screen
6. Open the linked page <- You will see a yellow screen on startup of the page

### Not working example

https://github.com/user-attachments/assets/0aee2a93-0aff-4f11-ab9e-d8585ca91204

In this example, I am simply using the `appleWebApp` property inside the Metadata object. https://github.com/jwanner83/next-apple-web-app-issue/blob/main/working-with-workaround/app/layout.tsx#L6 (This used to work before v15.0.0 / before the pull request https://github.com/vercel/next.js/pull/70363 was merged and released)

7. Go to [not-working](https://github.com/jwanner83/next-apple-web-app-issue/tree/main/not-working)
8. `pnpm i`
9. `pnpm dev`
10. Visit the page with an iPhone and add the page to the home screen
11. Open the linked page <- You will see a black screen on startup of the page, not the desired yellow startup image.

### Current vs. Expected behavior

I understand that the tag `apple-mobile-web-app-capable` is marked as deprecated and should be replaced with mobile-`web-app-capable` but for the sake of not breaking things, that safari requires, I would want the tag to be added in addition to the `mobile-web-app-capable`. 

### Provide environment information

```bash
Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.2.0: Fri Dec  6 19:02:12 PST 2024; root:xnu-11215.61.5~2/RELEASE_ARM64_T6031
  Available memory (MB): 36864
  Available CPU cores: 14
Binaries:
  Node: 20.18.1
  npm: 10.8.2
  Yarn: 1.22.22
  pnpm: 9.15.2
Relevant Packages:
  next: 15.1.1-canary.25 // Latest available version is detected (15.1.1-canary.25).
  eslint-config-next: N/A
  react: 19.0.0
  react-dom: 19.0.0
  typescript: 5.3.3
Next.js Config:
  output: N/A
```


### Which area(s) are affected? (Select all that apply)

Metadata

### Which stage(s) are affected? (Select all that apply)

next dev (local), next start (local), Vercel (Deployed)

### Additional context

The pull request https://github.com/vercel/next.js/pull/70363 which fixes the issue https://github.com/vercel/next.js/issues/70272 changed from the meta tag `<meta name="apple-mobile-web-app-capable" content="yes" />` to `<meta name="mobile-web-app-capable" content="yes" />` because apparently chrome tells the user that `apple-mobile-web-app-capable` is deprecated and should be replaced with `mobile-web-app-capable`. It was released with v15.0.0-canary.175 / v15.0.0

Unfortunately, the extremely bad documented apple splash screen feature for pwa https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ConfiguringWebApplications.html doesn't work when the `<meta name="apple-mobile-web-app-capable" content="yes" />` isn't set. 

The problem only occurres on iPhone devices.