Haven't run into this. Everything I've needed during this epidemic has been available, and most shipments have been on time or only slightly delayed.
Chains, brake pads, brake levers, bar tape, cables and housing, hardware, tires, etc. - found everything I needed. I'm rebuilding a mixte for my wife and got everything she wanted on order last night and today.
I have a few domestic vendors I buy from, and never order anything directly from the far east, never shopped on Ali Express. Universal Cycles is one place that has always come through for me.