If people are ok with "live and let live", yes. If not, there will be a lot of bickering ("why did they get an exception and me not?!"). Or senior management will be unhappy with their metrics ("we said three days in the office, and the average is just 2,78? Not acceptable!") - so rules might get tightened, as in my employer's case. Which also has the (in management's opinion, beneficial) side effect of getting rid of some of those pesky "troublemakers" who insist on having more home office than management wants them to have, without a severance package.