I think this is only temporary. It is probably going to be reverted soon. (I might be remembering this wrong.) For now you can try to use hopper minecarts for quicker item movement maybe?
This is a major preventative for lag. There are many users like yourself using ridiculously long dropper chains to transport pork across distances, and powering the droppers 4-5 times per second. This was most likely the reason the dropper cool down was implemented in the first place. People are not smart though and will just add more dropper chains or towers to get around the nerf, creating more lag than there was in the first place. With a 2 alt limit this reduced speed of pork in droppers is no longer needed as long as staff keep the ridiculously big ones under control. Moving 16 pork at a time is not a good implementation as players use droppers to give free pork and have various other uses for droppers that require them to stay as they are.