Yes, indeed. I wish people wouldn't recommend using EasyTAG because
it can't handle ID3 v2.4 (mainly because it still depends on the
obsolete and no longer updated id3lib library). Once you edit your
tags in rhythmbox you will no longer be able to edit them in EasyTAG.
For standalone mass retagging I recommend using the exfalso tag editor
which is part of quodlibet and handles ID3 v2.4 read/write and
recommend *not* using EasyTAG until such time as it upgrades to a
better tag rewriting library.
Alex