How long are modern variants of the F-16 expected to be in production?
An article last month in the Greenville News about the relocation of the F-16 production line provided this comment:


  The Trump administration fast-tracked a $1 billion F-16 deal with
  Bahrain, Navarro said. Deals closed or on the verge of closing since
  then guarantee the plant in Greenville will stay busy at least through
  2025 and likely much longer, he said.


The "likely much longer" will be based on future sales (and Government approval of those sales.) It's a good plane at a competitive price, but a change in the marketplace could mean it ends after this contract build.