Even if it is just my subjective experience, I've also been experiencing a veeeery low drop rates on cantina battle. Since the updates of course. Doing 36 battle a day for JC, and usually getting 4/5 shards. I've never experienced that. My Geo soldier was 7* before my Sid and lumi. And now I'm grinding QGJ faster than JC.
Of course we need a lot of tries to get a solid statistic to say "Yes, drop rates have been lowered", but according to many player's experience, something changed.
The argument that it is just our feeling and it depends on days won't satisfied players very long, in my opinion.