- Is it a GPL-only thing or can I use this formulation with any license, like "MPL 2 or later"?
- Does it mean that in case versions 1, 2 & 3 of license are available, "version 1 or later" effectively licenses the project under all 3 of them?
- Can I formulate it so only the latest version of license would apply at any given time? Does it change with the condition of including license text?
Adding a statement of "or later" to your license notice effectively dual-licenses your project, so yes, in general, you can do this. But Technik Empire raised a good point that future versions of the license may not be compatible. For example, if your GPL v2 code depends on some other GPL v2-only code, then you couldn't upgrade yours to GPL v3.
Whether you would want to when you don't know the terms of future versions is another question. Licenses sometimes change in substantial ways. The GPL-3 has changes which many people care a lot about, and later Creative Commons licenses change how attribution must be made. If you're happy enough with a license to choose it, then I'd recommend just sticking with it. You can always reevaluate and explicitly dual-license your project if the license is revised in the future.
Yeah that's right, it is dual- (or multi-) licensed under all those licenses.
You can't change the license of something which has already been distributed. If someone received it under version 2 and wants to use it under that license and not version 3, they can. If you want to publish something only under the latest license, then don't publish under a "or later" clause, instead just update the license when a new version is released.