They're restricted in the sense that the health authorities stopped recommending a specific covid-19 vaccine for a particular demographic. That demographic -- young males under 30 -- are recommended and given a vaccine from another vendor (practically Pfizer) instead.
That's rather different than the impression you might get from "these vaccines being restricted", or something similar.
That's actually not true, people who got the first dose of moderna will not get a second one, and it's being stopped for all persons under 30, not just males. In practice it will be stopped for everyone above 30 as well.
/Swede