UPDATE:
I wrote a letter and submitted in writing to both the listing agent and the asset manager at the bank.
The gist of the letter is "I am Kris Fox of xxx, LLC. I have an ownership interest in ABC property and have an executed contract. I am writing to notify you that I plan on enforcing my rights."
After submitting it, I realized I forgot to write "...rights in regard to the encroachment"
"This is a piece of paper...is there an actual contract? First of all, I do not see how any material fact regarding the ownership of "ABC Property" has changed from what the current buyers are already aware of, they are fully aware the bank does not own that lot, and it is not part of their purchase agreement with the bank. The present owner could absolutely "enforce her rights", whatever it is they mean by that?? Do they have some legal basis, or some additional information on what rights exactly they are referring to? If so, that might be something they would want to include in this "notice" they have provided us with. This note/notice as presented seems almost like a threat of some kind? They are welcome to clarify what action they intend to pursue against ABC Property. Our legal staff is already looking into how it came to pass that these lots were separated prior to foreclosure, any new information these folks want to share would be welcome. IF they had actually purchased/ and closed on the property from the seller of the lot, then that would be a material fact worth mentioning to the current buyers, but as far as your duty goes at this point, I don't see how anything has really changed?"
The contract has been forwarded with purchase price and closing date blacked out.
I plan on submitting a new letter that says "I plan on enforcing my rights in regards to the encroachment". It seems like that doesn't matter to him though until I own the property.