This is relatively old news.
I reported that link about two months ago.
VTC5's have been missing from stores shelves for several months or longer. VTC4's seem to be in relatively common supply still.
I'm not sure who actually makes Sony
batteries. My guess is that Sony commissioned multiple battery manufacturering plants to make cells for them. Sony made the decision to stop sponsoring these, but the factories making the cells seem to be still making them. Either that, or there were a lot of surplus VTC4's in warehouses waiting to be sold.
There's at least a couple of battery brands which use the original Sony VTC4 cell and re-wrap them under their own name:
xtar and Efest among them. So apparently there's a ready stock of them.
Orbtronics sells a fine 30 amp continuous battery (Orbtronics SX30 2100mah 30 amp), too. Any other manufacturer claiming 30 amps or more I'd be highly suspicious of.