It could also just have benign economic upsides. Fuel is cheaper than technology, launch can be managed with different parameters than for electronics, refuelling is a useful skill. Not that it doesn't have the risk side military/strategic consequences, more that it has upside benefits to China independently of the perceived downside risk consequences for the USA.

Sometimes a cigar is .. just an cigar. Sometimes China's imperatives point inwards not outwards.

Maybe refuelling is part of their cis lunar strategy?

Maybe not a new skill? China announces successful satellite in-orbit refuelling (2016) https://news.ycombinator.com/item?id=12034479