I accidently boiled porkchops will they ever be tender enough to at least pull appart/shred for bbq sandwiches?
It is unlikely that pork chops boiled will result in a finished product that will be shreddable.
This cut of meat comes from the loin area of the pig and is more suitable for roasting, grilling, pan frying.
If you want shreddable pork (pulled pork, carnitas, etc.), the appropriate cut would be something like the pork shoulder or rib and cooked low-and-slow (braised, slow BBQ, etc.) to soften the collagen in these tougher cuts.
Use this unfortunate experience as a lesson about judiciously picking the right cut of meat and using the appropriate cooking technique to produce an intended result/product.
As a workaround, hopefully you will be able to slice the meat thinly for sandwiches but you probably won't be able to shred it.
Anyhow, best of luck.
About the only way I can think of to get your pork chops deconstructed for sandwich use would be to cut them into smaller pieces and use a food processor. If you have any of the cooking liquid left, that will help get some much needed moisture into the meat and make the processor job a bit easier. Pulse it to get a more shredded consistency, but not so much you reduce it to mush. Then you can heat up the bbq sauce and mix that into the meat to heat it up gently. It's not going to be the best bbq pork sandwich you ever had, but it will help you rescue what you can.
Loin pork chops will shred just fine, though they're not fatty enough for most shredded pork dishes. You don't give much detail on the boiling, but you can probably braise them to the point where they'll shred- whether it's a good idea, I won't speculate.
I braise my porkchops all the time they are absolutely delicious. Brown on both sides, add chicken broth cover for one hour and let them simmer. They are fork tender when they are done and there’s so much nice caramelization in the bottom of the pan they get really gooey brown bits and are delicious. Not sure how much liquid you used and how long you cooked them.