I googled it - knowing that the source of targeted ECM can be targeted back -, but couldn’t find anything about the ECM Burst specifically. Seeing as the burst does what it says (jamming locks indiscriminately), I am not sure whether or not it still works.
Normal ECM is on a 20 second cycle and THAT one was changed so you can always target the one jamming you. Burst jammers work differently as they just break lock without any jamming cycle, those were not affected by the changes.