There are a couple of coins that did 100x over this period of time.
I'm not sure what are the coins you are referring but none of them are appreciating from the levels of 30 satoshi to 700+ satoshi but must be the unique case of dogecoins. Even bitcoin is known for rising up to 10x or 20x in four years of time but only very few altcoins got potential to do like this and here the potential could be anything and for the case of dogecoins it is like attracting investors for some reason and nothing more or nothing less.
There will not be a strong fall; against the general background, the cryptocurrency will fall in about the same way.
I strongly doubt it; because all the whales who are pumping dogecoins definitely will prefer to book profits at some price levels which cannot be predictable hence other investors and traders will be trapped at that time but this is an usual thing in this crypto space.
Check out Autumn/Winter 2017 and you will see how many tokens went 30x and more. It was serious insanity how these tokens all mooned out of a sudden. Dogecoin is another extreme case though as it goes up and up and up. Nobody knows where this coin will end up.