It's already possible. Post-training is vastly more important than model size. (There's bigtime diminishing returns with increasing model size.)
My experience doesn't disagree, at least. I've been using Qwen for coding locally a bit. It is much better than I thought it would be. But also still falls short in some obvious ways compared to the frontiers.
No idea yet. But also it's obvious that making LLMs without MoE is stupid.