A couple of points -
If I remember correctly, Bhai Manpreet Singh arranged to do Keertan at Darbar Sahib when he met Jathedar Vedanti a few weeks ago in Birmingham.
Also, it is my understanding that not any and every jatha can do Keertan at Darbar Sahib; rather it is only those that can adhere to Darbar Sahib's Maryada, which includes doing Keertan without pothees and in the relevant raag. At least this was how it was done in past times.