Package Platform Event in managed package

Question

I want to package a platform event in managed package. I know that after doing this my package cannot be installed in Professional or Group edition orgs. But I also see following while uploading my managed package:

So does all salesforce orgs which are not Professional, or group edition have this feature enabled by default or is it something that needs to be enabled separately. My package is created and supported only for orgs that are not Professional or Group edition, could there be any scenario where this package installation still fails after adding platform event to my package.

Edit 1: I read the provided question in comment: Can a Managed Package with Platform Events work in a Professional Edition Org

It does not answer my question because I specifically want to know about the features mentioned in the image above:

1. API and Platform Events
2. API and High Volume Platform Events

I am unaware if these features are directly linked with different editions of an org, i.e., not present in Professional or Group edition, and present in other editions.

Answer 1

Platform Events are available (as per documentation) in all Performance, Unlimited, Enterprise and Developer editions without the need to have it separately enabled.

This warning is simply indicating your package won't be compatible with Professional and Group edition orgs.

The only other scenario I can think of is where the org has already consumed all available Platform Event definitions. See the documentation for more detail on allocations. Specifically consider the note toward the end of the page:

Platform events that originate from an installed managed package share the org’s allocation for the maximum number of platform event definitions.

Note, however, that Salesforce doesn't always rigidly apply limits (some limits have become what they call "soft limits", with a larger and unpublished "hard limit" capping out what you can do).