When did the ranking system change?

I haven’t played for awhile but when did they change that you can drop from a diamond 1 to a Plat 6?

You’re quite late on this; the changes were made a good while back. I suppose it is meant to “prevent” players from hoarding high CSR placements in Arena, which could prove troublesome for less experienced players who are struggling in Arena on a particular basis.

The ability to drop ranks has been in the game for quite some time now

like other posts have said its been here for quite a while now. Around monitors bounty I believe. I hate it however.

Its been modified consistently recently

they did that like 6 months or so ago