It's good to get the word out, but typically, most Sheriff's Offices that handle SAR Ops do not want a bunch of spontaneous volunteers until after several operational periods, if they want any at all. Most agencies will ask other local counties or put out a State-wide request for trained SAR personnel.
It is common for them to alert the public so other hunters, hikers, etc, in the area are aware of the situation, but it is uncommon to have an agency openly ask for assistance from the general public for liability reasons. More often, the request comes from the family posting for help on social media, which makes the situation more complicated because the Sheriff's Office now has to manage these unknown, untrained resources.
Definitely good to get the word out, but I would urge the Moderators not to make a Call-for-Action post unless it's from the responsible agency.