Here's what was signed.
http://www.house.mo.gov/billtracking/bills161/billpdf/truly/HB1562T.PDF
Key items:
Pics of younger folks
Trafficking of another person.
Trafficking of younger folks (two different levels)
Stalking rules are also heavier.
Thus, pics, ads, etc, of consenting adults, on Backpage or other websites, do not appear to be impacted.
Of interest is that outfits like BP have had "publishing" issues previously settled by the us court of appeals, 1st district, case 15-1724, which judgment was issued march 2016.
Here's a link to that:
http://media.ca1.uscourts.gov/pdf.op...-1724P-01A.pdf
I seriously recommend drinking some coffee before reading either of these.