Scheduled URL alias creation

Is there an entity for the url alias, and does it have the concept of being published ? That is what Scheduler needs. See https://project.pages.drupalcode.org/scheduler/plugin/

Scheduler publishes the content, it does not change values of any other fields. There are other modules which might be able to do what you want - try Scheduled Updates? Alternatively if your client is using Content Moderation that you can use Scheduler with that, and the new revision (which gets published by Scheduler) would have the changed url alias value.

Here's a scenario that we had recently:

1. Unpublish node 1, remove its URL alias.
2. Publish node 2, update its URL alias to the value of the first node.

It wasn't possible to just schedule a draft node of node 1 as node 2 was a different content type.

I don't quite understand the scenario you describe in #5, but any way it is not related to making a new plugin for url aliases. I think this issue is a non-starter, unless you can find a "url alias" entity which can be scheduled independently.