I would respectfully point out that WP munitions are only banned if they are used with flammability as their primary purpose. If it is a secondary or ancillary purpose then they are not banned hence their usage following the bans without breaching the rules. It is good to see they are not using them though now as there are plenty of alternatives to suit the same purpose and you have to wonder what the screen is actually for in this case as I find a hard time seeing how they would actually need one.
gets people in doors and off the streets, hopefully reducing unnecessary civilian casualties from any fighting or explosive ordinance would be my guess.