If we're talking about actual clean-room reverse engineering where only the overall design or spec is copied and not the specific code, then yes. In this process, one person would decompile the original and turn it into a human-readable spec, and another person would write their own implementation. But the decompiled code itself is never distributed.
That's very different from the decompilation projects being discussed here, which do distribute the decompiled code.
These decompilation projects do involve some creative choices, which means that the decompilation would likely be considered a derivative work, containing copyrightable elements from both the authors of the original binary and the authors of the decompilation project. This is similar to a human translation of a literary work. A derivative work does have its own copyright, but distributing a derivative work requires permission from the copyright holders of both the original and the derivative. So a decompilation project technically can set their own license, and thereby add additional restrictions, but they can't overwrite the original license. If there is no original license, the default is that you can't distribute at all.