the reason i think MSTR did this for "repatriation" reasons is that onshore cash is usually held in t-bills and offshore cash is held in dollar denominated euro dollar bank accounts and michael has said that he used binance to make the initial purchases https://youtu.be/Jb48Q5e4WVg
which would only have been done with overseas dollars so he definitely moved dollars that could not easily be repatriated into bitcoin.
he may have had a melting ice cube but he had foreign dollars and this was his way of getting around a repatriation tax.