This law removes legal restrictions that might have made it impossible for researchers to openly redistribute those articles.
But this will generally be combined with grant funding rules that require to provide the research results under open access conditions. So yes, people will publish their articles because they are willing to jump through almost any hoops to fulfill the funding requirements; and blacklisting is unlikely since in that case they'd have to blacklist all France now and generally all EU, which is slowly but strongly moving to a requirement to have all EU-funded research published with free access.
But this will generally be combined with grant funding rules that require to provide the research results under open access conditions. So yes, people will publish their articles because they are willing to jump through almost any hoops to fulfill the funding requirements; and blacklisting is unlikely since in that case they'd have to blacklist all France now and generally all EU, which is slowly but strongly moving to a requirement to have all EU-funded research published with free access.