Wait, you're the chain fairy?
Yeah, the bolt suggestion was obviously devil's advocacy, but it points up an interesting Gunks dilemma. People will get all twisted about an unobtrusive pair of bolts, yet seem willing to put up with this crap:
Look, if you really want an anchor there so much so that you want to put a bolt, why don't you save yourself some trouble and time and run a stainless or galvanized steel cable off another tree or rock back in the woods. Yea, and take a rubber hose on it too. You can inspect a cable but anyone can crazy glue a bolt to the wall. In other words, there is no disadvantage to using a cable. All you need to know is how long to make the cable, cut it, and put the hose and six clamps on it, and don't saddle a dead horse. It should take you no longer than 5 minutes to install it, less time than it took me to write this post. Hopefully no one will trip over it and fall off the cliff, if they do it is your fault.
...and all the other convenience anchors made of shitty nuts, ancient pins, and multiple hunks of old webbing. Fixed anchors are fixed anchors - it doesn't matter what they are made from.
If a rappel tree is dieing, there's good chance it's from soil compaction at its base from climber foot traffic. Although it's probably too late for this tree, if you really want to save the tree, loosen the soil, aerate it, and put a little boardwalk around it - make sure the boardwalk extends to edge of the tree's canopy.