I think you need to go look at the backlog in semi conductor production before you say a few months to asic. More like a year+ at this point. Fpgas fork easily unlike asics. But again it is not the threat you claim it is….there simply isnt the magnitude of volume of fpgas and the cost is sufficient to keep it that way for now.
They will only tell they are producing it publicly if they plan to sell or market it as to sell on a set date, many produced asics in the past and kept for themselves for years till they decided to sell because they had something else better to let in their warehouse. Bitmain is known to do that, anyway, those practices are common known, not sure why you asked me to check semiconductor backlog, they ask for discretion here, when lots of money is involved and they dont want people to know then nobody will know about it.