So in FFF-266 we learned that 0.17 will remove the glorious steelaxe from the game. We have suffered a terrible loss. R.I.P. Steelaxe, you were too young.

"So the change for 0.17 is that we completely removed mining tools from the game. The mining speed at the game start is the same as with iron pickaxe, and the research that unlocked steel pickaxe just increases player mining speed accordingly and that is it."

https://www.factorio.com/blog/post/fff-266

So does this mean that Steelaxe% will only remain a category for 0.16 and lower? Or will the timer stop when the research to increase speed is complete?

We will have a major 0.17 rule changes discussion once the new version is released. All Speedrunners are invited to join the discussion, make rule change proposals and vote on the results eventually.