Bitmain has learnd its mistakes before for damaging global hashrate of some coins. The current Bitmain only release low speed ASIC and only one per customer outside China and Hong Kong which is good. The miner Z9 only worth 14 of 1080 TI or you can say Antminer Z9 x1 = one Rig of 1080 OC x12 which have the same speed around 10kh. Current Equihash global hashrate around 800mh so even if Bitmain release 10.000 Z9, it will only worth 100mh and thats only 12.5% increased difficulty IF its really 10.000 miner. Usually they only release <5k per batch so total around 6.25% increased difficulty. The next batch usually just around a month with the same amount should just increase difficulty by 5% or so.

I guess Bitmain try to use "soft approch" for the coins so it can accept ASIC and killing GPU sales. Just a remainder, it works with E3 that only have RX580 x6 speed and ETH accept it.