I don’t know what the governance setup is like, but in theory the owners of the project can change the license to whatever they like at any time.
The catch is that this doesn’t affect old versions, which remain available under the old license. So they could make WP closed-source or make the license more restrictive, but WP-engine or any portion of the community could make a fork and maintain the open source version from there. It wouldn’t have the features added by the mainline WP project since the license change (and they’d likely have to change the branding), but that’s about all that would be lost.
Similar things have happened in the past: see OpenOffice becoming LibreOffice for example.
I don’t know what the governance setup is like, but in theory the owners of the project can change the license to whatever they like at any time.
The catch is that this doesn’t affect old versions, which remain available under the old license. So they could make WP closed-source or make the license more restrictive, but WP-engine or any portion of the community could make a fork and maintain the open source version from there. It wouldn’t have the features added by the mainline WP project since the license change (and they’d likely have to change the branding), but that’s about all that would be lost.
Similar things have happened in the past: see OpenOffice becoming LibreOffice for example.