There are Ford filters that do not have "S" in the part number that DO have a silicone ADBV.
The reason is, I believe, because those filters that do have an S in the part number (FL-400S and FL-820S are all that I know about) were once available without a silicone ADBV, and the S was added to identify the new, improved model. (I believe the silicone ADBV was added to the FL-820S in 1995 or 1996, and that filter dates back to 1991 when it was introduced along with the 4.6L V8 that it fits).
Apparently, those that have a silicone ADBV and do not have an S in the part number were never made without one. I believe, if you check, you will find that the FL-200 and the FL-2005 have a silicone ADBV, and they were introduced in 1995 and 1998 respectively.