People keep saying "bitmain mines with them for months before releasing them". In the case of Sia, someone said bitmain "clearly" mined for 45 days before releasing. I was there looking when Sia ASICs came out, I can for sure say that bitmain didn't mine a single day before shipping them, ASIC introduction is obvious in a small coin like Sia.
Now in the case of Monero, the entire network today is equivalent to about 4000 X3s. Clearly there is no room there for bitmain to have been "mining with the X3s for months".
7000 more-or-less if you include ALL CN coins - but most of the extra is ETN which has also announced plans to change their algorithm.
Ballpark 500 if you count ALL of the CN coins combined except XMR and ETN.
No way Bitmain has been mining with thousands of X3 units for months, most of the hashrate growth happened in November-January timeframe can EASILY be explained by the timeframe of when those "Vega are crazy Monero miners" guides started popping up and when the massive Vega shortage hit.
The later jump in late Febuary MIGHT have been X3 production units going online, but some of it would be "Vegas from 3'd party manufactures become widely available for sale and are IN STOCK" even with the inflated pricing on most of those GPUs.