+1 to this, and -1 to the proposal for that reason. And it's not commutative either (which x could imply), since InlineArray<5, Int> is not the same as InlineArray<Int, 5>.
I also tend to agree that if InlineArray is a niche type as was mentioned in its own pitch and review threads, it doesn't warrant any syntax sugar either (at least until it gets wide enough adoption), particularly as special and controversial as the one being proposed.