That is what a "sealing" means for most members of The Church of Jesus Christ of Latter-day Saints. However, for Chad it appears to be something completely different and not in harmony with the Church's definition.
He lists Joseph Ryan as a level 4.3 Dark spirit (whatever that even means. He didn't pick up this teaching from the Church, but either picked it up from someone else, or made it up himself). This is apparently a bad thing and, according to Chad, "4.1 and above have made covenants to their side. They rarely switch sides." Meaning, as I understand it, Chad and/or his followers believe JR (being a level 4.3 dark spirit) made covenants with Satan to work for him and is therefore evil incarnate and is likely beyond redemption ("they rarely switch sides.").
My best educated guess is that Chad's saying that JR is "sealed away" is either 1) some twisted perversion of the Church's doctrine of "sealing" (i.e. JR made a marriage covenant of sorts with Satan?), or 2) some kind of reference to the sons of perdition, of whom it might be said that their fate is "sealed" to be cast into a lake of fire and brimstone with the devil and his angels, according to the scriptures (see Doctrine and Covenants 76:31-38). I'm guessing this latter one is what he has in mind since he says that JR is a dark (or evil) spirit.
Either way, Chad's beliefs as written in that email are completely foreign to and/or a twisted perversion of the teachings of the Church.
And what's also disturbing is that he lists Tylee as a level 4.1 dark spirit, meaning they also believed she was beyond redemption and likely wouldn't ever become a "light" spirit. The reason I find this disturbing is because it provides motive for why Tylee, Lori's own daughter, "disappeared" before JJ did, something I could never figure out before now. JJ is listed as a 4.2 Light spirit, but then probably "turned dark" after Tylee "disappeared" and so they felt he needed to be "disappeared" too. I feel sick. MOO.