Regardless of whether it's legal (it should be, but ask a lawyer), as a maintainer I find it inappropriate. For software that has a single primary author and many contributors of small patches, an appropriate copyright notice looks like:
Copyright ©2019 [author's name], et. al.
for et alia, literally "and others".
For a work with multiple major authors (and it's not clear to me the point at which this should change), but with no formal organization holding copyright, a more appropriate version might be:
Copyright ©2019 the authors of [project name]
However, you might want to run this by a lawyer, since it's not entirely traditional/conventional.
If you do end up with a formal organization that will hold copyright to most of the work, but don't want to impose FSF-style copyright assignment, an appropriate notice would be:
Copyright ©2019 [The Organization], et. al.