The closing agent is not required to provide a 1099-S if the SALES PRICE is less than $250,000 / $500,000. They may still opt to do so. If they issue a 1099-S, you must report that on your tax return.
@rjs - the closing agent would not know what the capital gains would be; they would only know what the sales price is. The form you suggest is only available if the selling price is less than $250,000 / $500,000. See the "exception" paragraph in the link below.
https://www.irs.gov/pub/irs-pdf/i1099s.pdf
