In practical terms, OEMs already specifying FTDI chips into their products are likely to continue doing so, since their gear will continue to work fine, either because they have their own VID/PIDs and drivers, or because FTDI drivers have continued to work fine.
OEMs specifying (or allowing) knockoffs are likely to have a hard think - either stay as they were, move to a known vendor, whether that's FTDI or other (possibly going down the driverless CDC route), or some third option I can't think of at the moment. Maybe rip off FTDI's drivers, register a VID/PID (maybe orphaned, if they want it for free?) and deliver a driver / chip combo. Driver certification under modern Windows might be an issue? Those super-cheap 'how do they make it so cheap, and ship it for that?' widgets might cost an extra dollar.
The side effect of temporary (but severe) annoyance for some of the end purchasers of gear containing FTDI knockoffs - yeah, it's an annoyance, and seems to have been done hamfistedly. They're in no way FTDI customers, or probable future FTDI customers. There's a clear recovery route for the damaged hardware. Several, even, and more are likely (and scams based on them, no doubt - 'download FTDIfix.exe and run it as administrator, answer yes to all prompts'...).
However, from FTDI's point of view - isn't this a clear message? Buy legit chips, or stop using FTDI drivers and identification? It could surely have gone better, but I'm not seeing it as a calamity.