So? How ethnic Russians anywhere entitle Russia to invade exactly? And what do you think would happened to minorities everywhere if that logic would be bought?
The question was "what does Moscow want with Moldova?" Not "is Russia entitled to invade/install a friendly regime in Moldova?"
In that case, Russians or Russian speaking don't matter. They are an excuse, but not necessary for Moscow to do what they want.
By this logic, the US should be justifiably invaded by a dozen other countries at least.