Another Burmese participant suggested a weirder explanation for the absence of celebrations. Public holidays are usually days for protests: licensed and unlicensed, across nine districts (to be fined by each of the nine districts' mayors) or round and round the Sule Pagoda. These are days of protest, by conservatives and liberals and landowners and farmowners and copper mines, when visiting journalists are so bewildered they don't know which rally to cover.
So when Independence Day comes, the government doesn't want to make too big a fuss of it. Just in case, y'know. Something happens.