I'd wait until he's actually released. Only then would I reach out to him to kick the tires.
The Broncos did the same thing with Randy Gregory. They put it out to the media that he was being released, but never actually did it. Instead, they forced the 49'ers hand to part with a late-round draft pick.
I'm not in favor of the Rams parting with any draft capital for players they don't plan to re-sign.
I'm keeping a weary eye on Dotson for this reason.