No, this is not correct at all! You keep limiting yourself to the terms “open source” and “closed source”.
Any code you create, you own by copyright. Even if it is public on GitHub, you’re still the lone copyright owner and no one is legally allowed to do with it what isn’t allowed by a license.
Projects on GitHub without an open source license are only “functionally open source” to the same extent that pirated games are “functionally free”.
Everyone in this thread is already using Linux and just using this thread to circlejerk about issues the average Windows user won’t care about.