In the order of change if there is to be one it may not be something like an increase in the number of miles needed to qualify but it could instead be something like for gold you need your four qualifying sectors on A3 to be in paid business class. The tiers above gold on SQ and LH both have similar criteria attached to them and in fact no matter how many economy miles you fly you will never make the top tiers with only them. The top tiers on SQ and LH benefit only those airlines in financial terms and that's also the only place you get extras above *G.
If A3 moved to all four qualifying sectors in business on their own metal and increased the qualifying thresholds for anyone qualifying without the four sectors I wonder how numbers of golds would be affected. Back in the day when BD was the alternative to M&M in Europe you had to initially qualify on full fare sectors (four IIRC) before you could join Diamond Club. That was before their membership of *A so it had to be their own metal.