A Pint Is Not a Unit of Measurement
Someday in the future, the word "pint" will lose all meaning as a unit of measurement. A "pint" will simply mean a glass of beer. Saying "a pint of beer" will be as ridiculous as saying "a beer of beer."
In other words, ordering a pint at your local pub is perfectly fine in a metric world. A pint is no more a unit of measurement than a glass. A glass of beer is generally about 500 ml, but it varies a lot just like a pint. A pint is not a unit of measurement.
If you prefer your beer in a can, you can order a "tinnie" instead of a pint.
It's Just a Ton
Eventually there will only be a single meaning of the word "ton" for weight, and it will unambiguously mean exactly 1,000 kg. Today, unfortunately, we have the British ton (long ton), metric ton (tonne), and U.S. ton (short ton). Crazy.
The spelling of the word "tonne" is bizarre — that farcical word needs to die out. Saying "metric ton" solves the ambiguity problem, but it's redundant like saying "metric liter". Even if it takes 100 years, the ridiculous and inefficient jumble of ton units will be relegated to the dustbin of history, and a ton will just be a ton.