Unfortunately, it's not such easy. Skipper isn't "Database" tool, Skipper is ORM tool and because of that Skipper doesn't know anything if the project is deployed on MySQL, SQL Server or anything else.
This what you're describing is a work of ORM, not Skipper. Skipper is exporting ORM migrations, not database migrations.
Laravel should know that MySQL doesn't support such change and Larave should "fix it" by creating a temporary column, migrating data, destroying the column, and renaming the column.
This is the primary purpose of ORM. To hide implementation details of every DB and offer a single API.
So as I wrote earlier, Laravel has to fix it (or MySQL), not Skipper, which knows nothing about target DB.