I looked up some examples of uncountable nouns to try to test the theory that all uncountable nouns can be made countable, by seeing if a forced pluralized version of an uncountable noun is ever used. There are many examples of uncountable nouns that can definitely be made countable and are used in plural forms in legitimate ways — for example, "art" is given as an example of an uncountable noun, but people do talk about "the arts" in many contexts.
There are also some uncountable nouns that can be forced and stretched into countable nouns if you give a really specific and esoteric situation, like "rice" can maybe debatably become "rices" if you were talking about several different kinds of rice, but like I said, this sort of thing is a stretch.
Then there are some uncountable nouns that refuse to play this game at all. "Luggage" does not become "luggages" in any circumstance. "Information" will not become "informations" no matter how many edge-case contexts you try. You can use these forms of these words, but they're going to sound goofy and comedic. You won't be able to use these forced plurals in serious contexts and continue to be taken seriously.
So, in conclusion, no, you cannot make ALL uncountable nouns into countable nouns. I'll leave it to someone else to test if the reverse is true, if all countable nouns can be made uncountable.