Bitmain like Baikal were mining with X3 monero to death, and now that Cryptonight coins are forking (switching algo) they are getting rid of the useless equipment.
I strongly suspect this was going on as well for Baikal.
In the case of Bitmain, I suspect their hand was forced because Baikal beat them to the punch and Monero announced they would hard fork.
Bitmain appears to be still in development of their asic, hence the "conservative" hashrate estimates on the production miner but they needed to get this out for pre-order to try and capitalize before the upcoming Cryptonight forks. People that don't know any better will still buy and some people with tons of money, will buy anyways in hopes that the gamble pays off.
I wouldn't be surprised if Bitmain or someone stands up their own pool and forks XMR so these asics will still work after the core XMR chain forks to a revised algo
(Disclaimer: This is purely speculation or "conspiracy theory" on my part and I have no inside knowledge that indicates any such activity will happen, it's just a gut feeling)
This can be a reason for hackers to attach XMR ! If bitmain will own the 51% of the network ,,, good bye security ,, welcome to bitmain attack
Don't forget what happen to Antpool (bitmain),, hacker attack from bitmain to their own pool .... same like nicehash ,,, they hacked themselves