GAFillerCells site

Hi all,

I red in a Cadence application note from November 2014, that "GACells is GACORE site based filler insertion while GAFillerCells is CORE site based filler insertion".

However, in my LEF file it is written:

MACRO GFILL
    CLASS CORE ;
    SITE gacore7T ;

And when I try the command
ecoPlace -useGAFillerCells {GFILL}
it is written
**ERROR: (ENCSP-2707):    TechSite 'gacore7T' used by the GAFiller list does not have rows in the design.

Maybe, the easiest way to overcome that is to change the LEF file in
SITE core7T ;

but I'm wondering, will it still work during the ECO flow ?
Will SoC put GA Cells at the place of GA fillers which have a SITE core ?

Thanks a lot !