This news is surprising when factoring in the very low cost of a ERFA Tender Offer and the versatility (CB, Kickoff Returner, and Special Teams Coverage) of Khalil Dorsey.
In looking at the list from the following site, which I saw from at least one other source, Khalil Dorsey is scheduled to be a RFA, not a ERFA. If Dorsey is indeed a RFA, the Lions decision not to tender him makes sense. With the realistic possibility the two parties would work out a contract.