The queues there are genuinely insane, but it's not really about "handing out" free tickets. The Hermitage has had a system in place for ages: the first Thursday of every month is free for everyone, plus there are discounted hours for certain categories. The scheme has been running for years, so it's not news to locals and tourists who plan their visits specifically around those days. That's where the crowds come from - concentrating people at the same time creates a real bottleneck.
But here's what matters: not all hours on those days are equally hellish. If you show up when the museum opens (usually around 10-11 in the morning), there will be a line, but it moves noticeably faster. By noon - already a nightmare, by evening - even worse. I'd suggest going either first thing in the morning or on a Tuesday or Wednesday afternoon, when it's a paid day and there are way fewer people. An hour in line is not normal, you just need to rethink when you're visiting.
As for whether it's permanent - yeah, it's not a special promotion, it's the museum's regular policy. But a lot of people just don't know about it until they end up in the crowd themselves. If you want to skip the lines, buy a ticket in advance online for a paid day - it's cheap, and the payoff is huge.