ASRock z270 Taichi bios 2.20 removed from download

The rule of thumb with BIOS/UEFI is this:

Is your system working properly?

If yes

forget about it and enjoy your PC 

In this case however we are waiting for intel to get a new fix out to board partners so the exploit can be patched. I see a lot of panic surrounding this but ultimately, this issue is largely a threat for the business/enterprise end of the market. The average user is no more likely to be targeted through the exploit than they were before the exploit was discovered. Lets face it, home/small business PCs don't typically have very effective security set up anyway, it just isn't cost effective. The major issue with meltdown (the one that needs a UEFI update to correct) is that it allows hackers to bypass even the most sophisticated (net connected) security setups. A huge issue for things like banks, hospitals, law enforcement, corporations etc. 

Off track a bit there but relevant in that it is (most likely) the reason the update was pulled. If you have already updated to it then you don't need to do anything, just wait for the next update and flash to that when it is released. You may encounter the odd random shut down but from what I have seen this is not a common or frequent issue and will not harm your PC in any way. It is simply a nuisance.