There's an obvious advantage to everyone speaking the same language - although perhaps real-time translation with LLMs and hardware like the Timekettle will reduce this problem. Personally, I wouldn't really care if that language were English or Mandarin Chinese tbh.

Training an entire LLM model for each language is going to be incredibly expensive and likely a waste of resources. Keep in mind that all the big LLMs can already speak these languages anyway - this effort is just to make a 'pure' Portuguese LLM.